fcdmft.gw.pbc.krgw_ac module#
PBC spin-restricted G0W0-AC QP eigenvalues with k-point sampling This implementation has N^4 scaling, and is faster than GW-CD (N^4) and analytic GW (N^6) methods. GW-AC is recommended for valence states only, and is inaccurate for core states.
- Method:
T. Zhu and G.K.-L. Chan, J. Chem. Theory. Comput. 17, 727-741 (2021) Compute Sigma on imaginary frequency with density fitting, then analytically continued to real frequency. Gaussian density fitting must be used (FFTDF and MDF are not supported).
Note: MPI only works for GW code (DFT should run in serial)
- class fcdmft.gw.pbc.krgw_ac.KRGWAC(mf, frozen=None)[source]#
Bases:
StreamObject- Attributes:
- nmo
- nocc
Methods
__call__(*args, **kwargs)Update the attributes of the current object.
apply(fn, *args, **kwargs)Apply the fn to rest arguments: return fn(*args, **kwargs). The return value of method set is the object itself. This allows a series of functions/methods to be executed in pipe.
check_sanity()Check input of class/object attributes, check whether a class method is overwritten.
copy()Returns a shallow copy
kernel([orbs, kptlist])Run a G0W0 calculation.
make_gf(omega, eta)Get dynamical Green's function and self-energy.
make_rdm1([ao_repr])Get GW density matrix from Green's function G(it=0).
post_kernel(envs)A hook to be run after the main body of the kernel function.
pre_kernel(envs)A hook to be run before the main body of kernel function is executed.
run(*args, **kwargs)Call the kernel function of current object.
set(*args, **kwargs)Update the attributes of the current object.
Set .frozen attribute from frozen mask.
view(cls)New view of object with the same attributes.
dump_flags
- make_gf(omega, eta)#
Get dynamical Green’s function and self-energy.
- Parameters:
- gwKRGWAC
GW object, provides attributes: orbs, kptlist, ef, ac_coeff, omega_fit, vk, vxc, _scf.mo_energy
- omegadouble or complex
array frequency grids
- etadouble
broadening parameter
- Returns:
- make_rdm1(ao_repr=False)#
Get GW density matrix from Green’s function G(it=0). G is from linear Dyson equation, which conserves particle number G = G0 + G0 Sigma G0 See equation 16 in 10.1021/acs.jctc.0c01264
- property nmo#
- property nocc#
- set_frozen_orbs()#
Set .frozen attribute from frozen mask.
- Parameters:
- gwKRGWAC
unrestricted GW object
- fcdmft.gw.pbc.krgw_ac.get_ef(kmf, mo_energy)[source]#
Get Fermi level. For gapped systems, Fermi level is computed as the average between HOMO and LUMO. For metallic systems, Fermi level is optmized according to mo_energy.
- Parameters:
- kmfpyscf.pbc.scf.rhf.RHF/pyscf.pbc.dft.rks.RKS
mean-field object, provides attributes: kpts, sigma, smearing_method
- mo_energydouble
array orbital energy
- Returns:
- efdouble
Fermi level
- fcdmft.gw.pbc.krgw_ac.get_g0_k(omega, mo_energy, eta)[source]#
Get non-interacting Green’s function.
- fcdmft.gw.pbc.krgw_ac.get_qij(gw, q, mo_energy, mo_coeff, uniform_grids=False)[source]#
Compute pair density matrix in the long-wavelength limit through kp perturbation theory qij = 1/Omega * |< psi_{ik} | e^{iqr} | psi_{ak-q} >|^2 equation 51 in 10.1021/acs.jctc.0c00704 Ref: Phys. Rev. B 83, 245122 (2011)
- Parameters:
- Returns:
- qijcomplex
ndarray pair density matrix in the long-wavelength limit
- qijcomplex
- fcdmft.gw.pbc.krgw_ac.get_rho_response(omega, mo_energy, Lia, kidx)[source]#
Get Pi=PV. P is density-density response function. V is two-electron integral. See equation 24 in 10.1021/acs.jctc.0c00704
- fcdmft.gw.pbc.krgw_ac.get_rho_response_head(omega, mo_energy, qij)[source]#
Compute head (G=0, G’=0) density response function in auxiliary basis at freq iw. equation 48 in 10.1021/acs.jctc.0c00704
- fcdmft.gw.pbc.krgw_ac.get_rho_response_metal(omega, mo_energy, mo_occ, Lpq, kidx)[source]#
Get Pi=PV for metallic systems. P is density-density response function. V is two-electron integral. See equation 24 in 10.1021/acs.jctc.0c00704
- Parameters:
- Returns:
- Picomplex
ndarray Pi in auxiliary basis at freq iw
- Picomplex
- fcdmft.gw.pbc.krgw_ac.get_rho_response_wing(omega, mo_energy, Lia, qij)[source]#
Compute wing (G=P, G’=0) density response function in auxiliary basis at freq iw. equation 48 in 10.1021/acs.jctc.0c00704
- Parameters:
- Returns:
- Picomplex
ndarray wing response function
- Picomplex
- fcdmft.gw.pbc.krgw_ac.get_sigma(gw, freqs, wts, ef, mo_energy, orbs=None, kptlist=None, mo_coeff=None, mo_occ=None, iw_cutoff=None, fullsigma=False)[source]#
Get GW self-energy. See equation 27 in 10.1021/acs.jctc.0c00704
- Parameters:
- gwKRGWAC
GW objects, provides attributes: _scf, mol, frozen, nmo, nocc, kpts, nkpts, mo_coeff, mo_occ, fc, fc_grid, with_df
- freqsdouble
array position of imaginary frequency
- wtsdouble
array weight of frequency points
- efdouble
Fermi level
- mo_energydouble
ndarray non-frozen orbital energy
- orbs
list, optional orbital index in non-frozen nmo to calculate self-energy, by default None
- kptlist
list, optional k-point index to calculate self-energy, by default None
- mo_coeffcomplex
ndarray, optional coefficient from AO to non-frozen MO, by default None
- mo_occdouble
ndarray, optional non-frozen occupation number, by default None
- iw_cutoffcomplex, optional
imaginary grid cutoff for fitting, by default None
- fullsigmabool, optional
calculate off-diagonal elements, by default False
- Returns:
- fcdmft.gw.pbc.krgw_ac.make_gf(gw, omega, eta)[source]#
Get dynamical Green’s function and self-energy.
- Parameters:
- gwKRGWAC
GW object, provides attributes: orbs, kptlist, ef, ac_coeff, omega_fit, vk, vxc, _scf.mo_energy
- omegadouble or complex
array frequency grids
- etadouble
broadening parameter
- Returns: