Excited-state Coupled Cluster methods

ElemCo.EOM — Module
 module EOM

This module contains the implementation of the EOM (Equation of Motion) methods for computing the excited states.

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Exported functions

ElemCo.EOM.calc_svd_eom — Method
calc_svd_eom(EC::ECInfo, method::ECMethod)

Calculate decomposed closed-shell EOM-DCSD.

Currently only DC methods are supported. DF integrals are used (have to be calculated before).

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Internal functions

ElemCo.EOM.cis_HU1 — Method
cis_HU1(EC::ECInfo, U1)

Compute H times U1 for CIS.

$V^i_a = f_a^c U^i_c - f_k^i U^k_a + (2 v_{ak}^{ic} - v_{ak}^{ci}) U^k_c$

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ElemCo.EOM.cis_homo_lumo_guess — Method
cis_homo_lumo_guess(EC, nstates)

generate a CIS starting guess for nstates by preparing a CIS matrix around the HOMO-LUMO and diagonalizing it

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ElemCo.EOM.new_u_trial_vector! — Method
new_u_trial_vector!(EC, vecs, omega)

Calculate new unrestricted trial vector using residuals from vecs.

vecs is a tuple (U1a, U1b, U2a, U2b, U2ab). Updates the vectors in place.

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ElemCo.EOM.ucis_HU1 — Method
ucis_HU1(EC::ECInfo, U1, U1os, spin)

Compute H times U1 for unrestricted CIS. U1 are the singles of spin∈{:α,:β}, U1os are the opposite-spin singles.

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ElemCo.EOM.ucis_homo_lumo_guess — Method
ucis_homo_lumo_guess(EC, nstates)

Generate an unrestricted CIS starting guess for nstates by preparing a CIS matrix around the HOMO-LUMO and diagonalizing it.

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