Hello All,
I sort of stated this question earlier but was not particularly clear the first time so let me try again. I am attempting to get off-diagonal elements of the hamiltonian matrix between Molecular Orbitals of two different fragments.
My test system right now is two Helium atoms. When I do the two helium fragment calculations and read them into a dimer calcultions with "print debug" in my input file, I find the fock matrix printed as such:
Direct Fock builds = 1
Atom quartets computed = 0 ( 0.00%)
Shell quartets rejected = 0 ( 0.00%)
Shell quartets computed = 0 ( 0.00%)
Integral file = ./He2_dir_test_rhf.aoints.0
Record size in doubles = 65536 No. of integs per rec = 43688
Max. records in memory = 2 Max. records in file = 1373608
No. of bits per label = 8 No. of bits per value = 64
int2e_file: wrote 40 integrals in record 1 of 1.
Symmetrized combined AO fock matrices
global array: rohf: cfock[1:4,1:4], handle: -990
1 2 3 4
----------- ----------- ----------- -----------
1 -0.07072 -1.11782 0.00396 -0.03237
2 -1.11782 -0.50026 -0.03237 -0.07256
3 0.00396 -0.03237 -0.07072 -1.11782
4 -0.03237 -0.07256 -1.11782 -0.50026
global array: rohf_init: FCV[1:4,1:4], handle: -996
1 2 3 4
----------- ----------- ----------- -----------
1 -0.92466 0.00000 0.00393 -0.00000
2 0.00000 -0.88165 -0.00000 -0.00474
3 0.00393 -0.00000 1.97472 -0.00000
4 -0.00000 -0.00474 -0.00000 2.21186
To my dismay this states that the "rohf_init" is indeed the AO Fock matrix and not the Fock matrix between the MOs of fragments, even though what I read in was the Molecular orbitals from each fragment. Is the best option just to get all of the MO coefficients and AO integrals and do the four-index transformation myself, and put the pieces together for what the off diagonal of the Hamiltonian are?
I am only interested in HOMO-LUMO couplings so this seems kind of like overkill to me, and there might be an easier way.
Thank you for your time,
-Cole
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