Davidson solver

Davidson solver module

Davidson object

addvecs!(dav::Davidson, tvecs, prods)

Add trial and product vectors to Davidson object and update effective Hamiltonian matrix.

dav_normalize!(vecs, vecs2)

Normalize vectors vecs and rescale vecs2 accordingly.

dav_normalize!(vecs)

Normalize vectors.

diagonalize(dav::Davidson)

Diagonalize effective Hamiltonian matrix.

orthogonalize!(dav::Davidson, vecs)

Orthogonalize vectors to trial vectors.

perform!(dav::Davidson, tvecs_nst, prods_nst, states)

Perform Davidson algorithm.

tvecs_nst and prods_nst are trial and product vectors for each state.

perform!(dav::Davidson, tvecs, prods)

Perform Davidson algorithm.

tvecs and prods are trial and product vectors for the first state.

addprodvecs!(dav::Davidson, prods)

Add product vectors to Davidson object and update effective Hamiltonian matrix.

addtrialvecs!(dav::Davidson, tvecs)

Add trial vectors to Davidson object and update effective overlap matrix (in non-hermitian case).

Note: tvecs will be orthogonalized and normalized.

addtrialvecs4allstates!(dav::Davidson, tvecs_nst)

Add trial vectors to Davidson object and update effective overlap matrix (in non-hermitian case).

tvecs_nst are trial vectors for each state.

combine!(dav::Davidson, outvec, vecfiles, coeffs)

Combine vectors from files with coefficients.

outvec is the output vector.

combine(dav::Davidson, vecfiles, coeffs)

Combine vectors from files with coefficients.

hermitian(dav::Davidson)

Check if Davidson object is hermitian.

loadprods(dav::Davidson, ipos)

Load product vectors from file at position ipos as Vector{Vector{Float64}}.

loadtvecs(dav::Davidson, ipos)

Load trial vectors from file at position ipos as Vector{Vector{Float64}}.

loadvecs(file)

Load vectors from file as Vector{Vector{Float64}}.

saveprods(dav::Davidson, vecs)

Save vectors to next file.

savetvecs(dav::Davidson, vecs)

Save trial vectors to next file.

update_Heff!(dav::Davidson, tvecs, prods)

Update effective Hamiltonian matrix.

tvecs and prods are trial and product vectors (for one state) for the current iteration of Davidson algorithm (stored at dav.nDim position).

update_Heff!(dav::Davidson, prods)

Update effective Hamiltonian matrix (symmetrically).

prods are product vectors (for one state) for the current iteration of Davidson algorithm (stored at dav.nDim position).

update_Seff!(dav::Davidson, tvecs)

Update effective overlap matrix.

tvecs are trial vectors (for one state) for the current iteration of Davidson algorithm (stored at dav.nDim position).