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the_scf_program [2025/09/25 11:56] – update spin+irrep dollthe_scf_program [2025/09/25 13:22] (current) – RHF only high-spin doll
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 Note that these values take sensible defaults if any or all are not specified (see section [[general program structure#symmetry|symmetry]]). For example, ''%%{rhf; wf,sym=N,spin=M}%%'' gives the explicit values N for the symmetry and M for the spin of the wave function, but uses the default number of electrons. Note that these values take sensible defaults if any or all are not specified (see section [[general program structure#symmetry|symmetry]]). For example, ''%%{rhf; wf,sym=N,spin=M}%%'' gives the explicit values N for the symmetry and M for the spin of the wave function, but uses the default number of electrons.
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 +In HF/RHF, the spin has to be equal to the number of singly occupied orbitals, i.e. the electrons couple to a high-spin state. For example, an open-shell singlet state cannot be described on this level. Instead, for states which are not high-spin, MCSCF has to be used.
  
 ==== Defining the number of occupied orbitals in each symmetry ==== ==== Defining the number of occupied orbitals in each symmetry ====