diff --git a/examples/20-finite_size_corrections.py b/examples/20-finite_size_corrections.py new file mode 100644 index 00000000..523faeea --- /dev/null +++ b/examples/20-finite_size_corrections.py @@ -0,0 +1,46 @@ +""" +Examples of finite size corrections for `momentGW` calculations for periodic solids. +""" + +import numpy as np +from pyscf.pbc import dft, gto + +from momentGW import KGW, KUGW + +# Define a unit cell +cell = gto.Cell() +cell.atom = "He 0 0 0; He 1 1 1" +cell.basis = "6-31g" +cell.a = np.eye(3) * 3 +cell.verbose = 5 +cell.build() +kpts = cell.make_kpts([3, 1, 1]) + +# Run a DFT calculation +mf = dft.KRKS(cell, kpts) +mf = mf.density_fit() +mf.xc = "b3lyp" +mf.kernel() + +# For any `pbc` calculation a finite size correction can be added for +# the divergence associated with G = 0, q=0 for GDF Coulomb integrals. +# This is done by setting the `fsc` attribute to any combination of +# "H", "W", and/or "B" for the Head, Wings and Body portion of the +# correction. The Ewald correction is added in all cases. The default +# is `None` which disables the correction. + +# RHF reference +gw = KGW(mf) +gw.polarizability = "dRPA" +gw.fsc = "HWB" +gw.kernel(nmom_max=3) + +gw = KGW(mf) +gw.polarizability = "dTDA" +gw.fsc = "HW" +gw.kernel(nmom_max=3) + +gw = KGW(mf) +gw.polarizability = "dRPA" +gw.fsc = "H" +gw.kernel(nmom_max=3) diff --git a/momentGW/gw.py b/momentGW/gw.py index e1d715fc..e4ebffbc 100644 --- a/momentGW/gw.py +++ b/momentGW/gw.py @@ -144,9 +144,37 @@ def name(self): polarizability = self.polarizability.upper().replace("DTDA", "dTDA").replace("DRPA", "dRPA") return f"{polarizability}-G0W0" + def get_veff(self, integrals, dm=None, **kwargs): + """Get the effective potential. + + Parameters + ---------- + integrals : Integrals + Integrals object. + dm : numpy.ndarray, optional + Density matrix. If `None`, determine using `self.make_rdm1`. + Default value is `None`. + **kwargs : dict, optional + Additional keyword arguments passed to the integrals object. + + Returns + ------- + veff : numpy.ndarray + Effective potential. + """ + + # Get the density matrix + if dm is None: + dm = self.make_rdm1() + + # Get the effective potential + veff = integrals.get_veff(dm, **kwargs) + + return veff + @logging.with_timer("Static self-energy") @logging.with_status("Building static self-energy") - def build_se_static(self, integrals): + def build_se_static(self, integrals, force_build=False): """ Build the static part of the self-energy, including the Fock matrix. @@ -155,6 +183,10 @@ def build_se_static(self, integrals): ---------- integrals : Integrals Integrals object. + force_build : bool, optional + If `True`, force the static self-energy to be built, even if + the underlying mean-field object is Hartree--Fock. Default + value is `False`. Returns ------- @@ -168,7 +200,7 @@ def build_se_static(self, integrals): dm = self._scf.make_rdm1(mo_coeff=self._mo_coeff) # Get the contribution from the exchange-correlation potential - if getattr(self._scf, "xc", "hf") == "hf": + if getattr(self._scf, "xc", "hf") == "hf" and not force_build: se_static = np.zeros_like(dm) se_static = se_static[..., mask, :][..., :, mask] else: @@ -176,7 +208,7 @@ def build_se_static(self, integrals): veff = self._scf.get_veff(None, dm)[..., mask, :][..., :, mask] vj = self._scf.get_j(None, dm)[..., mask, :][..., :, mask] - vhf = integrals.get_veff(dm, j=vj, basis="ao") + vhf = self.get_veff(integrals, dm=dm, j=vj, basis="ao") se_static = vhf - veff se_static = util.einsum( "...pq,...pi,...qj->...ij", se_static, np.conj(self.mo_coeff), self.mo_coeff diff --git a/momentGW/pbc/base.py b/momentGW/pbc/base.py index 016b8669..7f28e165 100644 --- a/momentGW/pbc/base.py +++ b/momentGW/pbc/base.py @@ -52,14 +52,14 @@ class BaseKGW(BaseGW): thc_opts : dict, optional Dictionary of options to be used for THC calculations. Current implementation requires a filepath to import the THC integrals. - fc : bool, optional + fsc : bool, optional If `True`, apply finite size corrections. Default value is `False`. """ _defaults = OrderedDict( **BaseGW._defaults, - fc=False, + fsc=None, ) _defaults["compression"] = None @@ -70,7 +70,7 @@ def __init__(self, mf, **kwargs): super().__init__(mf, **kwargs) # Options - self.fc = False + self.fsc = None # Attributes self._kpts = KPoints(self.cell, getattr(mf, "kpts", np.zeros((1, 3)))) diff --git a/momentGW/pbc/gw.py b/momentGW/pbc/gw.py index f0991ea6..c4809171 100644 --- a/momentGW/pbc/gw.py +++ b/momentGW/pbc/gw.py @@ -56,7 +56,7 @@ class KGW(BaseKGW, GW): thc_opts : dict, optional Dictionary of options to be used for THC calculations. Current implementation requires a filepath to import the THC integrals. - fc : bool, optional + fsc : bool, optional If `True`, apply finite size corrections. Default value is `False`. """ @@ -69,9 +69,44 @@ def name(self): polarizability = self.polarizability.upper().replace("DTDA", "dTDA").replace("DRPA", "dRPA") return f"{polarizability}-KG0W0" + def get_veff(self, integrals, dm=None, **kwargs): + """Get the effective potential. + + Parameters + ---------- + integrals : KIntegrals + Integrals object. + dm : numpy.ndarray, optional + Density matrix at each k-point. If `None`, determine using + `self.make_rdm1`. Default value is `None`. + **kwargs : dict, optional + Additional keyword arguments passed to the integrals object. + + Returns + ------- + veff : numpy.ndarray + Effective potential at each k-point. + """ + + # Get the density matrix + if dm is None: + dm = self.make_rdm1() + + # Set the default options + if "ewald" not in kwargs: + if self.fsc is not None: + kwargs = {**kwargs, "ewald": True} + else: + kwargs = {**kwargs, "ewald": False} + + # Get the effective potential + veff = integrals.get_veff(dm, **kwargs) + + return veff + @logging.with_timer("Static self-energy") @logging.with_status("Building static self-energy") - def build_se_static(self, integrals): + def build_se_static(self, integrals, **kwargs): """ Build the static part of the self-energy, including the Fock matrix. @@ -80,6 +115,8 @@ def build_se_static(self, integrals): ---------- integrals : KIntegrals Integrals object. + **kwargs : dict, optional + Additional keyword arguments. Returns ------- @@ -87,7 +124,20 @@ def build_se_static(self, integrals): Static part of the self-energy at each k-point. If `self.diagonal_se`, non-diagonal elements are set to zero. """ - return super().build_se_static(integrals) + if self.fsc is not None: + if len(list(self.fsc)) > 3: + raise ValueError( + "Finite size corrections require as an input a combination of H, W and B " + "for the different finite size corrections (H - Head, W - Wing, B - Body)") + for i, letter in enumerate(list(self.fsc)): + if letter not in ["H", "W", "B"]: + raise ValueError( + "Finite size corrections require as an input a combination of H, W and B " + "for the different finite size corrections (H - Head, W - Wing, B - Body)") + kwargs = {**kwargs, "force_build": True} + else: + kwargs = {**kwargs, "force_build": False} + return super().build_se_static(integrals, **kwargs) def build_se_moments(self, nmom_max, integrals, **kwargs): """Build the moments of the self-energy. @@ -112,10 +162,10 @@ def build_se_moments(self, nmom_max, integrals, **kwargs): """ if self.polarizability.lower() == "dtda": - tda = dTDA(self, nmom_max, integrals, **kwargs) + tda = dTDA(self, nmom_max, integrals, fsc=self.fsc, **kwargs) return tda.kernel() if self.polarizability.lower() == "drpa": - rpa = dRPA(self, nmom_max, integrals, **kwargs) + rpa = dRPA(self, nmom_max, integrals, fsc=self.fsc, **kwargs) return rpa.kernel() elif self.polarizability.lower() == "thc-dtda": tda = thc.dTDA(self, nmom_max, integrals, **kwargs) @@ -154,6 +204,8 @@ def ao2mo(self, transform=True): compression=self.compression, compression_tol=self.compression_tol, store_full=self.fock_loop, + mo_energy_w=self.mo_energy, + fsc=self.fsc, input_path=self.thc_opts["file_path"], ) @@ -334,7 +386,7 @@ def make_rdm1(self, gf=None): @logging.with_timer("Energy") @logging.with_status("Calculating energy") - def energy_hf(self, gf=None, integrals=None): + def energy_hf(self, gf=None, integrals=None, **kwargs): """Calculate the one-body (Hartree--Fock) energy. Parameters @@ -367,7 +419,7 @@ def energy_hf(self, gf=None, integrals=None): "kpq,kpi,kqj->kij", self._scf.get_hcore(), self.mo_coeff.conj(), self.mo_coeff ) rdm1 = self.make_rdm1() - fock = integrals.get_fock(rdm1, h1e) + fock = integrals.get_fock(rdm1, h1e, **kwargs) # Calculate the Hartree--Fock energy at each k-point e_1b = sum(energy.hartree_fock(rdm1[k], fock[k], h1e[k]) for k in self.kpts.loop(1)) diff --git a/momentGW/pbc/ints.py b/momentGW/pbc/ints.py index 56c7de70..34953184 100644 --- a/momentGW/pbc/ints.py +++ b/momentGW/pbc/ints.py @@ -2,13 +2,11 @@ Integral helpers with periodic boundary conditions. """ -from collections import defaultdict - import h5py import numpy as np from pyscf import lib from pyscf.ao2mo import _ao2mo -from pyscf.pbc import tools +from pyscf.pbc import dft, tools from scipy.linalg import cholesky from momentGW import logging, mpi_helper, util @@ -47,6 +45,8 @@ def __init__( compression="ia", compression_tol=1e-10, store_full=False, + mo_energy_w=None, + fsc=None, input_path=None, ): Integrals.__init__( @@ -61,12 +61,15 @@ def __init__( # Options self.input_path = input_path + self.fsc = fsc # Attributes self.kpts = kpts self._madelung = None self._naux_full = None self._naux = None + if mo_energy_w is not None: + self.mo_energy_w = mo_energy_w @logging.with_status("Computing compression metric") def get_compression_metric(self): @@ -202,6 +205,12 @@ def transform(self, do_Lpq=None, do_Lpx=True, do_Lia=True): # ao2mo function for both real and complex integrals tao = np.empty([], dtype=np.int32) + # Building plane waves for finite size corrections + if self.fsc is not None: + q_abs = self.kpts.cell.get_abs_kpts(np.array([1e-3, 0, 0]).reshape(1, 3)) + hwb_const = np.sqrt(4.0 * np.pi) / np.linalg.norm(q_abs[0]) + pw = hwb_const * self.build_pert_term(q_abs[0]) + def _ao2mo_e2(Lpq, mo_coeff, orb_slice, out=None): mo_coeff = np.asarray(mo_coeff, order="F") if np.iscomplexobj(Lpq): @@ -215,6 +224,7 @@ def _ao2mo_e2(Lpq, mo_coeff, orb_slice, out=None): Lpx = {} Lia = {} Lai = {} + Mia = {} for q in self.kpts.loop(1): for ki in self.kpts.loop(1, mpi=True): @@ -338,6 +348,9 @@ def _ao2mo_e2(Lpq, mo_coeff, orb_slice, out=None): Lai[ki, kj] = Lai_k + if q == 0 and self.fsc is not None: + Mia[ki] = np.vstack([pw[ki], Lia[ki, ki]]) + # Store the arrays if do_Lpq: self._blocks["Lpq"] = Lpq @@ -346,6 +359,8 @@ def _ao2mo_e2(Lpq, mo_coeff, orb_slice, out=None): if do_Lia: self._blocks["Lia"] = Lia self._blocks["Lai"] = Lai + if self.fsc is not None: + self._blocks["Mia"] = Mia def get_cderi_from_thc(self): """ @@ -398,7 +413,7 @@ def get_cderi_from_thc(self): Lpx[ki, kj] = Lpx_k Lia[ki, kj] = Lia_k - q = self.kpts.member(self.kpts.wrap_around(-self.kpts[q])) + invq = self.kpts.member(self.kpts.wrap_around(-self.kpts[q])) block_switch = util.einsum("Pp,Pq,PQ->Qpq", coll_kj.conj(), coll_ki, cholesky_cou) @@ -408,7 +423,7 @@ def get_cderi_from_thc(self): ) tmp = util.einsum("Lpq,pi,qj->Lij", block_switch, coeffs[0].conj(), coeffs[1]) tmp = tmp.swapaxes(1, 2) - tmp = tmp.reshape(self.naux[q], -1) + tmp = tmp.reshape(self.naux[invq], -1) Lai_k += tmp Lai[ki, kj] = Lai_k @@ -552,6 +567,9 @@ def get_k(self, dm, basis="mo", ewald=False): basis : str, optional Basis in which to build the K matrix. One of `("ao", "mo")`. Default value is `"mo"`. + ewald : bool, optional + Whether to include the Ewald exchange divergence. Default + value is `False`. Returns ------- @@ -663,15 +681,57 @@ def get_ewald(self, dm, basis="mo"): # Get the overlap matrix if basis == "mo": - ovlp = defaultdict(lambda: np.eye(self.nmo)) + ovlp = np.concatenate([np.eye(self.nmo) for _ in self.kpts]) else: ovlp = self.with_df.cell.pbc_intor("int1e_ovlp", hermi=1, kpts=self.kpts._kpts) # Initialise the Ewald matrix - ew = util.einsum("kpq,kpi,kqj->kij", dm, ovlp.conj(), ovlp) + ew = self.madelung * util.einsum("kpq,kpi,kqj->kij", dm, np.conj(ovlp), ovlp) return ew + def build_pert_term(self, qpt): + """ + Build the charge-density density matrix at q-point index qpt + using perturbation theory. + + Parameters + ---------- + qpt : numpy.ndarray + q-point index representing the limit of our plane waves. + + Returns + ------- + pw_hw : numpy.ndarray + Charge-density density matrix in the long wavelength limit. + """ + + coords, weights = dft.gen_grid.get_becke_grids(self.kpts.cell, level=5) + + pw_hw = np.zeros((len(self.kpts),), dtype=object) + for k in self.kpts.loop(1): + ao_p = dft.numint.eval_ao(self.kpts.cell, coords, kpt=self.kpts[k], deriv=1) + ao, ao_grad = ao_p[0], ao_p[1:4] + + ao_ao_grad = util.einsum("g,gm,xgn->xmn", weights, ao.conj(), ao_grad) + q_ao_ao_grad = util.einsum("x,xmn->mn", qpt, ao_ao_grad) * -1.0j + q_mo_mo_grad = util.einsum( + "mn,mi,na->ia", + q_ao_ao_grad, + self.mo_coeff_w[k][:, self.mo_occ_w[k] > 0].conj(), + self.mo_coeff_w[k][:, self.mo_occ_w[k] == 0], + ) + + d = util.build_1h1p_energies( + (self.mo_energy_w[k], self.mo_energy_w[k]), + (self.mo_occ_w[k], self.mo_occ_w[k]), + ) + + dens = q_mo_mo_grad / d + pw_hw[k] = dens.flatten() / np.sqrt(self.kpts.cell.vol) + + return pw_hw + def get_jk(self, dm, **kwargs): """Build the J and K matrices. @@ -732,13 +792,19 @@ def get_fock(self, dm, h1e, **kwargs): """ return super().get_fock(dm, h1e, **kwargs) + def reciprocal_lattice(self): + """ + Return the reciprocal lattice vectors. + """ + return self.with_df.cell.reciprocal_vectors() + @property def madelung(self): """ Return the Madelung constant for the lattice. """ if self._madelung is None: - self._madeling = tools.pbc.madelung(self.with_df.cell, self.kpts._kpts) + self._madelung = tools.pbc.madelung(self.with_df.cell, self.kpts._kpts) return self._madelung @property @@ -746,6 +812,12 @@ def Lai(self): """Get the full uncompressed ``(aux, MO, MO)`` integrals.""" return self._blocks["Lai"] + @property + def Mia(self): + """Get the finite size corrected uncompressed ``(1+ aux, MO, MO)`` + integrals.""" + return self._blocks["Mia"] + @property def nmo(self): """Get the number of MOs.""" diff --git a/momentGW/pbc/rpa.py b/momentGW/pbc/rpa.py index 332a7944..7e3deb68 100644 --- a/momentGW/pbc/rpa.py +++ b/momentGW/pbc/rpa.py @@ -71,14 +71,19 @@ def _build_diag_eri(self): for q in self.kpts.loop(1): for ki in self.kpts.loop(1, mpi=True): - kb = self.kpts.member(self.kpts.wrap_around(self.kpts[q] + self.kpts[ki])) - diag_eri[q, kb] = ( - np.sum(np.abs(self.integrals.Lia[ki, kb]) ** 2, axis=0) / self.nkpts - ) + if q == 0 and self.fsc is not None and "B" in self.fsc: + diag_eri[q, ki] = ( + np.sum(np.abs(self.integrals.Mia[ki]) ** 2, axis=0) / self.nkpts + ) + else: + kb = self.kpts.member(self.kpts.wrap_around(self.kpts[q] + self.kpts[ki])) + diag_eri[q, kb] = ( + np.sum(np.abs(self.integrals.Lia[ki, kb]) ** 2, axis=0) / self.nkpts + ) return diag_eri - def _build_Liad(self, Lia, d): + def _build_Liad(self, Lia, d, corrected=False): """Construct the ``Liad`` array. Returns @@ -92,12 +97,15 @@ def _build_Liad(self, Lia, d): for q in self.kpts.loop(1): for ki in self.kpts.loop(1, mpi=True): - kb = self.kpts.member(self.kpts.wrap_around(self.kpts[q] + self.kpts[ki])) - Liad[q, kb] = Lia[ki, kb] * d[q, kb] + if q == 0 and corrected: + Liad[q, ki] = self.integrals.Mia[ki] * d[q, ki] + else: + kb = self.kpts.member(self.kpts.wrap_around(self.kpts[q] + self.kpts[ki])) + Liad[q, kb] = Lia[ki, kb] * d[q, kb] return Liad - def _build_Liadinv(self, Lia, d): + def _build_Liadinv(self, Lia, d, corrected=False): """Construct the ``Liadinv`` array. Returns @@ -111,8 +119,11 @@ def _build_Liadinv(self, Lia, d): for q in self.kpts.loop(1): for ki in self.kpts.loop(1, mpi=True): - kb = self.kpts.member(self.kpts.wrap_around(self.kpts[q] + self.kpts[ki])) - Liadinv[q, kb] = Lia[ki, kb] / d[q, kb] + if q == 0 and corrected: + Liadinv[q, ki] = self.integrals.Mia[ki] / d[q, ki] + else: + kb = self.kpts.member(self.kpts.wrap_around(self.kpts[q] + self.kpts[ki])) + Liadinv[q, kb] = Lia[ki, kb] / d[q, kb] return Liadinv @@ -136,16 +147,16 @@ def integrate(self): diag_eri = self._build_diag_eri() # Get the offset integral quadrature - quad = self.optimise_offset_quad(d, diag_eri) + quad_off = self.optimise_offset_quad(d, diag_eri) # Perform the offset integral - offset = self.eval_offset_integral(quad, d) + offset = self.eval_offset_integral(quad_off, d) # Get the main integral quadrature - quad = self.optimise_main_quad(d, diag_eri) + quad_main = self.optimise_main_quad(d, diag_eri) # Perform the main integral - integral = self.eval_main_integral(quad, d) + integral = self.eval_main_integral(quad_main, d) # Report quadrature error if self.report_quadrature_error: @@ -166,7 +177,12 @@ def integrate(self): f"(half = [{style_half}]{a:.3e}[/], quarter = [{style_quar}]{b:.3e}[/])", ) - return integral[0] + offset + if self.fsc is not None: + integral_fsc = self.eval_main_integral_fsc(quad_main, d) + offset_fsc = self.eval_offset_integral_fsc(quad_off, d) + return integral[0] + offset, integral_fsc[0] + offset_fsc + else: + return integral[0] + offset, None @logging.with_timer("Density-density moments") @logging.with_status("Constructing density-density moments") @@ -184,7 +200,24 @@ def build_dd_moments(self, integral=None): moments : numpy.ndarray Moments of the density-density response. """ - + integral, integral_fsc = self.integrate() + moments = self.build_uncorrected_dd_moments(integral) + if self.fsc is not None: + corrected_moments = self.build_corrected_dd_moments(integral_fsc) + for i in range(self.nmom_max + 1): + for kj in self.kpts.loop(1, mpi=True): + if "B" in self.fsc: + moments[0, kj, i] = corrected_moments[kj, i] + else: + moments[0, kj, i] = np.concatenate( + (np.array([corrected_moments[kj, i][0, :]]), moments[0, kj, i]) + ) + + return moments + else: + return moments + + def build_uncorrected_dd_moments(self, integral=None): if integral is None: integral = self.integrate() @@ -205,8 +238,9 @@ def build_dd_moments(self, integral=None): inter = 0.0 for kj in kpts.loop(1, mpi=True): kb = kpts.member(kpts.wrap_around(kpts[q] + kpts[kj])) - tmp += np.dot(Liadinv[q, kb], self.integrals.Lia[kj, kb].conj().T) + tmp += np.dot(Liadinv[q, kb], Lia[kj, kb].conj().T) inter += np.dot(integral[q, kb], Liadinv[q, kb].T.conj()) + tmp = mpi_helper.allreduce(tmp) inter = mpi_helper.allreduce(inter) tmp *= 2.0 @@ -225,10 +259,10 @@ def build_dd_moments(self, integral=None): for i in range(2, self.nmom_max + 1): for q in kpts.loop(1): tmp = 0.0 - for ka in kpts.loop(1, mpi=True): - kb = kpts.member(kpts.wrap_around(kpts[q] + kpts[ka])) + for kj in kpts.loop(1, mpi=True): + kb = kpts.member(kpts.wrap_around(kpts[q] + kpts[kj])) moments[q, kb, i] = moments[q, kb, i - 2] * d[q, kb] ** 2 - tmp += np.dot(moments[q, kb, i - 2], self.integrals.Lia[ka, kb].conj().T) + tmp += np.dot(moments[q, kb, i - 2], Lia[kj, kb].conj().T) tmp = mpi_helper.allreduce(tmp) tmp /= self.nkpts tmp *= 2 @@ -238,6 +272,55 @@ def build_dd_moments(self, integral=None): return moments + def build_corrected_dd_moments(self, integral_fsc=None): + if integral_fsc is None: + integral, integral_fsc = self.integrate() + + kpts = self.kpts + Mia = self.integrals.Mia + moments = np.zeros((self.nkpts, self.nmom_max + 1), dtype=object) + + # Construct the energy differences + d = self._build_d() + + # Calculate (L|ia) D_{ia} and (L|ia) D_{ia}^{-1} intermediates + Liad = self._build_Liad(self.integrals.Lia, d, corrected=True)[0] + Liadinv = self._build_Liadinv(self.integrals.Lia, d, corrected=True)[0] + + # Get the zeroth order moment + tmp = np.zeros((self.naux[0] + 1, self.naux[0] + 1), dtype=complex) + inter = 0.0 + for ka in kpts.loop(1, mpi=True): + tmp += np.dot(Liadinv[ka], Mia[ka].T.conj()) + inter += np.dot(integral_fsc[ka], Liadinv[ka].T.conj()) + + tmp = mpi_helper.allreduce(tmp) + inter = mpi_helper.allreduce(inter) + tmp *= 2.0 + u = np.linalg.inv(np.eye(tmp.shape[0]) * self.nkpts / 2 + tmp) + + rest = np.dot(inter, u) * self.nkpts / 2 + for ki in kpts.loop(1, mpi=True): + moments[ki, 0] = integral_fsc[ki] / d[0, ki] * self.nkpts / 2 + moments[ki, 0] -= np.dot(rest, Liadinv[ki]) * 2 + + # Get the first order moment + moments[:, 1] = Liad / self.nkpts + + # Get the higher order moments + for i in range(2, self.nmom_max + 1): + tmp = 0.0 + for ka in kpts.loop(1, mpi=True): + moments[ka, i] = moments[ka, i - 2] * d[0, ka] ** 2 + tmp += np.dot(moments[ka, i - 2], Mia[ka].conj().T) + tmp = mpi_helper.allreduce(tmp) + tmp /= self.nkpts + tmp *= 2 + for ki in kpts.loop(1, mpi=True): + moments[ki, i] += np.dot(tmp, Liad[ki]) * 2 + + return moments + def optimise_offset_quad(self, d, diag_eri, name="main"): """ Optimise the grid spacing of Gauss-Laguerre quadrature for the @@ -355,7 +438,6 @@ def eval_offset_integral(self, quad, d, Lia=None): lhs = mpi_helper.allreduce(lhs) lhs /= self.nkpts lhs *= 2 - for ka in kpts.loop(1, mpi=True): kb = kpts.member(kpts.wrap_around(kpts[q] + kpts[ka])) rhs = self.integrals.Lia[ka, kb] * np.exp(-point * d[q, kb]) @@ -365,6 +447,46 @@ def eval_offset_integral(self, quad, d, Lia=None): return integrals + def eval_offset_integral_fsc(self, quad, d): + """Evaluate the offset integral. + + Parameters + ---------- + quad : tuple + The quadrature points and weights. + d : numpy.ndarray + Orbital energy differences at each k-point. + + Returns + ------- + integral : numpy.ndarray + Offset integral. + """ + + # Get the integral intermediates + Mia = self.integrals.Mia + Liad = self._build_Liad(self.integrals.Lia, d, corrected=True)[0] + integrals = 2 * Liad / (self.nkpts**2) + + kpts = self.kpts + + # Calculate the integral for each point + for point, weight in zip(*quad): + lhs = 0.0 + for ka in kpts.loop(1, mpi=True): + expval = np.exp(-point * d[0, ka]) + lhs += np.dot(Liad[ka] * expval[None], Mia[ka].T.conj()) + lhs = mpi_helper.allreduce(lhs) + lhs /= self.nkpts + lhs *= 2 + for ka in kpts.loop(1, mpi=True): + rhs = Mia[ka] * np.exp(-point * d[0, ka]) + rhs /= self.nkpts**2 + res = np.dot(lhs, rhs) + integrals[ka] += res * weight * 4 + + return integrals + def optimise_main_quad(self, d, diag_eri, name="main"): """ Optimise the grid spacing of Clenshaw-Curtis quadrature for the @@ -531,3 +653,55 @@ def eval_main_integral(self, quad, d, Lia=None): integral[2, q, kb] += 4 * value return integral + + def eval_main_integral_fsc(self, quad, d): + """Evaluate the main integral. + + Parameters + ---------- + quad : tuple + The quadrature points and weights. + + Variables + ---------- + d : numpy.ndarray + Orbital energy differences at each k-point. + + Returns + ------- + integral : numpy.ndarray + Offset integral. + """ + + # Get the integral intermediates + Mia = self.integrals.Mia + Liad = self._build_Liad(self.integrals.Lia, d, corrected=True)[0] + + # Initialise the integral + dim = 3 if self.report_quadrature_error else 1 + integral = np.zeros((dim, self.nkpts), dtype=object) + + # Calculate the integral for each point + kpts = self.kpts + for i, (point, weight) in enumerate(zip(*quad)): + contrib = np.zeros_like(Liad, dtype=object) + f = np.zeros((self.nkpts), dtype=object) + qz = 0.0 + for ki in kpts.loop(1, mpi=True): + f[ki] = 1.0 / (d[0, ki] ** 2 + point**2) + pre = (Mia[ki] * f[ki]) * (4 / self.nkpts) + qz += np.dot(pre, Liad[ki].T.conj()) + qz = mpi_helper.allreduce(qz) + tmp = np.linalg.inv(np.eye(self.naux[0] + 1) + qz) - np.eye(self.naux[0] + 1) + inner = np.dot(qz, tmp) + for ki in kpts.loop(1, mpi=True): + contrib[ki] = 2 * np.dot(inner, Mia[ki]) / (self.nkpts**2) + value = weight * (contrib[ki] * f[ki] * (point**2 / np.pi)) + + integral[0, ki] += value + if i % 2 == 0 and self.report_quadrature_error: + integral[1, ki] += 2 * value + if i % 4 == 0 and self.report_quadrature_error: + integral[2, ki] += 4 * value + + return integral diff --git a/momentGW/pbc/tda.py b/momentGW/pbc/tda.py index 0ade92d6..e8eff868 100644 --- a/momentGW/pbc/tda.py +++ b/momentGW/pbc/tda.py @@ -34,6 +34,18 @@ class dTDA(MoldTDA): Default value is `None`. """ + def __init__( + self, + gw, + nmom_max, + integrals, + mo_energy=None, + mo_occ=None, + fsc=False, + ): + super().__init__(gw, nmom_max, integrals, mo_energy=mo_energy, mo_occ=mo_occ) + self.fsc = fsc + @logging.with_timer("Density-density moments") @logging.with_status("Constructing density-density moments") def build_dd_moments(self): @@ -45,6 +57,33 @@ def build_dd_moments(self): Moments of the density-density response at each k-point. """ + moments = self.build_uncorrected_dd_moments() + + if self.fsc is not None: + corrected_moments = self.build_corrected_dd_moments() + for i in range(self.nmom_max + 1): + for kj in self.kpts.loop(1, mpi=True): + if "B" in self.fsc: + moments[0, kj, i] = corrected_moments[kj, i] + else: + moments[0, kj, i] = np.concatenate( + (np.array([corrected_moments[kj, i][0, :]]), moments[0, kj, i]) + ) + + return moments + else: + return moments + + def build_uncorrected_dd_moments(self): + """Build the moments of the density-density response for + all k-point pairs. + + Returns + ------- + moments : numpy.ndarray + Moments of the density-density response at each k-point pair. + """ + # Initialise the moments kpts = self.kpts moments = np.zeros((self.nkpts, self.nkpts, self.nmom_max + 1), dtype=object) @@ -58,6 +97,7 @@ def build_dd_moments(self): # Get the higher order moments for i in range(1, self.nmom_max + 1): for q in kpts.loop(1): + tmp = np.zeros((self.naux[q], self.naux[q]), dtype=complex) for kj in kpts.loop(1, mpi=True): kb = kpts.member(kpts.wrap_around(kpts[q] + kpts[kj])) @@ -67,11 +107,7 @@ def build_dd_moments(self): ) moments[q, kb, i] += moments[q, kb, i - 1] * d.ravel()[None] - tmp = np.zeros((self.naux[q], self.naux[q]), dtype=complex) - for ki in kpts.loop(1, mpi=True): - ka = kpts.member(kpts.wrap_around(kpts[q] + kpts[ki])) - - tmp += np.dot(moments[q, ka, i - 1], self.integrals.Lia[ki, ka].T.conj()) + tmp += np.dot(moments[q, kb, i - 1], self.integrals.Lia[kj, kb].T.conj()) tmp = mpi_helper.allreduce(tmp) tmp *= 2.0 @@ -84,6 +120,42 @@ def build_dd_moments(self): return moments + def build_corrected_dd_moments(self): + """Build the finite size corrections for the moments of the + density-density response. + + Returns + ------- + moments : numpy.ndarray + Corrected moments of the density-density response at each + k-point for q=0. + """ + kpts = self.kpts + moments = np.zeros((self.nkpts, self.nmom_max + 1), dtype=object) + + # Get the zeroth order moment + for kj in kpts.loop(1, mpi=True): + moments[kj, 0] += self.integrals.Mia[kj] / self.nkpts + + # Get the higher order moments + for i in range(1, self.nmom_max + 1): + tmp = np.zeros((self.naux[0] + 1, self.naux[0] + 1), dtype=complex) + for kj in kpts.loop(1, mpi=True): + d = util.build_1h1p_energies( + (self.mo_energy_w[kj], self.mo_energy_w[kj]), + (self.mo_occ_w[kj], self.mo_occ_w[kj]), + ) + moments[kj, i] += moments[kj, i - 1] * d.ravel() + tmp += util.einsum("Pa,aQ->PQ", moments[kj, i - 1], self.integrals.Mia[kj].T.conj()) + tmp = mpi_helper.allreduce(tmp) + tmp *= 2.0 + tmp /= self.nkpts + + for kj in kpts.loop(1, mpi=True): + moments[kj, i] += util.einsum("PQ,Qa->Pa", tmp, self.integrals.Mia[kj]) + + return moments + def kernel(self, exact=False): """ Run the polarizability calculation to compute moments of the @@ -208,9 +280,11 @@ def build_se_moments(self, moments_dd): moments_vir : numpy.ndarray Moments of the virtual self-energy at each k-point. """ - kpts = self.kpts + if self.fsc is not None: + q0 = (6 * np.pi**2 / (kpts.cell.vol * self.nkpts)) ** (1 / 3) + # Setup dependent on diagonal SE if self.gw.diagonal_se: pqchar = pchar = qchar = "p" @@ -220,17 +294,18 @@ def build_se_moments(self, moments_dd): eta_shape = lambda k: (self.mo_energy_g[k].size, self.nmom_max + 1, self.nmo, self.nmo) eta = np.zeros((self.nkpts, self.nkpts), dtype=object) - # Get the moments in (aux|aux) and rotate to (mo|mo) for n in range(self.nmom_max + 1): for q in kpts.loop(1): eta_aux = 0 for kj in kpts.loop(1, mpi=True): - kb = kpts.member(kpts.wrap_around(kpts[q] + kpts[kj])) - eta_aux += np.dot(moments_dd[q, kb, n], self.integrals.Lia[kj, kb].T.conj()) + if q == 0 and self.fsc is not None: + eta_aux += np.dot(moments_dd[q, kj, n], self.integrals.Mia[kj].T.conj()) + else: + kb = kpts.member(kpts.wrap_around(kpts[q] + kpts[kj])) + eta_aux += np.dot(moments_dd[q, kb, n], self.integrals.Lia[kj, kb].T.conj()) eta_aux = mpi_helper.allreduce(eta_aux) eta_aux *= 2.0 - eta_aux /= self.nkpts for kp in kpts.loop(1, mpi=True): kx = kpts.member(kpts.wrap_around(kpts[kp] - kpts[q])) @@ -241,13 +316,44 @@ def build_se_moments(self, moments_dd): for x in range(self.mo_energy_g[kx].size): Lp = self.integrals.Lpx[kp, kx][:, :, x] subscript = f"P{pchar},Q{qchar},PQ->{pqchar}" - eta[kp, q][x, n] += util.einsum(subscript, Lp, Lp.conj(), eta_aux) + if q == 0 and self.fsc is not None: + eta[kp, q][x, n] += util.einsum( + subscript, Lp, Lp.conj(), eta_aux[1:, 1:] / self.nkpts + ) + if "H" in self.fsc and mpi_helper.rank == 0: + if self.gw.diagonal_se: + eta[kp, q][x, n][x] += (2 / np.pi) * q0 * eta_aux[0, 0] + else: + eta[kp, q][x, n][x, x] += (2 / np.pi) * q0 * eta_aux[0, 0] + if "W" in self.fsc: + wing_tmp = util.einsum( + f"P,P{pchar}{qchar}->{pqchar}", + eta_aux[0, 1:], + self.integrals.Lpx[kp, kx], + ) + wing_tmp = ( + (q0**2) * ((kpts.cell.vol / (4 * np.pi**3)) ** (1 / 2)) + ) * wing_tmp.real + if self.gw.diagonal_se: + eta[kp, q][x, n][x] += 2 * wing_tmp[x] + else: + eta[kp, q][x, n][x, :] -= wing_tmp.T[x, :] + eta[kp, q][x, n][:, x] -= wing_tmp[:, x] + else: + eta[kp, q][x, n] += util.einsum( + subscript, Lp, Lp.conj(), eta_aux / self.nkpts + ) # Construct the self-energy moments moments_occ, moments_vir = self.convolve(eta) return moments_occ, moments_vir + @property + def naux(self): + """Number of auxiliaries.""" + return self.integrals.naux + @property def nov(self): """Get the number of ov states in W.""" @@ -265,3 +371,8 @@ def kpts(self): def nkpts(self): """Get the number of k-points.""" return self.gw.nkpts + + @property + def q_abs(self): + """Get the absolute value of a region near the origin (q=0).""" + return self.kpts.cell.get_abs_kpts(np.array([1e-3, 0, 0]).reshape(1, 3)) diff --git a/momentGW/pbc/uhf/gw.py b/momentGW/pbc/uhf/gw.py index 646afde9..1f03b5d9 100644 --- a/momentGW/pbc/uhf/gw.py +++ b/momentGW/pbc/uhf/gw.py @@ -71,7 +71,7 @@ def name(self): @logging.with_timer("Static self-energy") @logging.with_status("Building static self-energy") - def build_se_static(self, integrals): + def build_se_static(self, integrals, **kwargs): """ Build the static part of the self-energy, including the Fock matrix. @@ -80,6 +80,8 @@ def build_se_static(self, integrals): ---------- integrals : KUIntegrals Integrals object. + **kwargs : dict, optional + Additional keyword arguments. Returns ------- @@ -88,7 +90,9 @@ def build_se_static(self, integrals): channel. If `self.diagonal_se`, non-diagonal elements are set to zero. """ - return super().build_se_static(integrals) + if "force_build" not in kwargs: + kwargs = {**kwargs, "force_build": self.fc} + return super().build_se_static(integrals, **kwargs) @logging.with_timer("Integral construction") @logging.with_status("Constructing integrals") diff --git a/momentGW/uhf/gw.py b/momentGW/uhf/gw.py index 48d1d979..5a4f83b3 100644 --- a/momentGW/uhf/gw.py +++ b/momentGW/uhf/gw.py @@ -75,7 +75,7 @@ def name(self): @logging.with_timer("Static self-energy") @logging.with_status("Building static self-energy") - def build_se_static(self, integrals): + def build_se_static(self, integrals, **kwargs): """ Build the static part of the self-energy, including the Fock matrix. @@ -84,6 +84,8 @@ def build_se_static(self, integrals): ---------- integrals : UIntegrals Integrals object. + **kwargs : dict, optional + Additional keyword arguments. Returns ------- @@ -91,7 +93,7 @@ def build_se_static(self, integrals): Static part of the self-energy for each spin channel. If `self.diagonal_se`, non-diagonal elements are set to zero. """ - return super().build_se_static(integrals) + return super().build_se_static(integrals, **kwargs) def build_se_moments(self, nmom_max, integrals, **kwargs): """Build the moments of the self-energy. diff --git a/momentGW/util.py b/momentGW/util.py index 7c0ffaf4..421236b5 100644 --- a/momentGW/util.py +++ b/momentGW/util.py @@ -456,7 +456,12 @@ def _fallback(): # Reshape and transpose the output ct = ct.reshape(shape_ct, order="A") - c = ct.transpose(order_ct) + if ct.flags.f_contiguous: + c = np.asfortranarray(ct.transpose(order_ct)) + elif ct.flags.c_contiguous: + c = np.ascontiguousarray(ct.transpose(order_ct)) + else: + c = ct.transpose(order_ct) return c diff --git a/tests/test_kgw.py b/tests/test_kgw.py index 928212bc..0202f92a 100644 --- a/tests/test_kgw.py +++ b/tests/test_kgw.py @@ -108,6 +108,47 @@ def test_drpa_vs_supercell(self): self._test_vs_supercell(gw, kgw, full=True) + def test_dtda_vs_supercell_frozen(self): + nmom_max = 3 + + kgw = KGW(self.mf) + kgw.polarizability = "dtda" + kgw.frozen = [0] + kgw.kernel(nmom_max) + + gw = GW(self.smf) + gw.__dict__.update({opt: getattr(kgw, opt) for opt in kgw._opts}) + gw.frozen = list(range(len(self.kpts))) + gw.kernel(nmom_max) + + self._test_vs_supercell(gw, kgw, full=True) + + def test_dtda_HW_regression(self): + nmom_max = 5 + kgw = KGW(self.mf) + kgw.polarizability = "dtda" + kgw.fsc = "HW" + conv, gf, se, _ = kgw.kernel(nmom_max) + gf_occ = gf[0].occupied().physical(weight=1e-1) + gf_vir = gf[0].virtual().physical(weight=1e-1) + self.assertAlmostEqual(np.max(gf_occ.energies[-1]), -0.7515760991553542, 6) + self.assertAlmostEqual(np.max(gf_occ.energies[-2]), -0.8924789480797911, 6) + self.assertAlmostEqual(np.max(gf_vir.energies[0]), 1.089967613154295, 6) + self.assertAlmostEqual(np.max(gf_vir.energies[1]), 1.883886215615475, 6) + + def test_drpa_HW_regression(self): + nmom_max = 5 + kgw = KGW(self.mf) + kgw.polarizability = "drpa" + kgw.fsc = "HWB" + conv, gf, se, _ = kgw.kernel(nmom_max) + gf_occ = gf[0].occupied().physical(weight=1e-1) + gf_vir = gf[0].virtual().physical(weight=1e-1) + self.assertAlmostEqual(np.max(gf_occ.energies[-1]), -0.7597568334841686, 6) + self.assertAlmostEqual(np.max(gf_occ.energies[-2]), -0.9002286289843537, 6) + self.assertAlmostEqual(np.max(gf_vir.energies[0]), 1.09266415629468, 6) + self.assertAlmostEqual(np.max(gf_vir.energies[1]), 1.8899834941075897, 6) + def test_dtda_vs_supercell_fock_loop(self): nmom_max = 5 @@ -168,21 +209,6 @@ def test_drpa_vs_supercell_compression(self): self._test_vs_supercell(gw, kgw, full=False, tol=1e-5) - def test_dtda_vs_supercell_frozen(self): - nmom_max = 3 - - kgw = KGW(self.mf) - kgw.polarizability = "dtda" - kgw.frozen = [0] - kgw.kernel(nmom_max) - - gw = GW(self.smf) - gw.__dict__.update({opt: getattr(kgw, opt) for opt in kgw._opts}) - gw.frozen = list(range(len(self.kpts))) - gw.kernel(nmom_max) - - self._test_vs_supercell(gw, kgw, full=True) - if __name__ == "__main__": print("Running tests for KGW")