This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision |
| the_nevpt2_program [2023/08/15 06:51] – [Input description] werner | the_nevpt2_program [2024/01/08 13:24] (current) – external edit 127.0.0.1 |
|---|
| Since Molpro2021.2, density fitting can be used to compute the integrals, and the program is then called with | Since Molpro2021.2, density fitting can be used to compute the integrals, and the program is then called with |
| ''DF-NEVPT2''. | ''DF-NEVPT2''. |
| | |
| | ''If you encounter an error exit'' due to non-zero Fock-matrix elements, the following can help: |
| | |
| | * In state-averaged CASSCF calculations, save state-specific canonical or natural orbitals in multi, e.g. for the second state in symmetry 1: ''NATORB,2141.2,state=2.1''. Do this for each state you want to treat by NEVPT2 with a different record. If you hit in multi the message "too many NATORB directives", you can use a subsequent CASCI calculation to add more NATORB directives. |
| | * Use the ''NOEXTRA'' directive in multi. |
| | * Add in nevpt2 the directives: ''PSPACE,1; OPTION, NSTATI=n; ORBITAL=record'', where n is the number of states you have optimized in multi for the current symmetry, and record is the record on which you have saved the orbitals for the state under consideration (in fact, what matters is the state-specific Fock matrix, which is saved along with the orbitals). |
| | |
| |
| ===== Input description ===== | ===== Input description ===== |