RIMP2: Essential Keywords

Apart from keywords $maxcor, $mp2energy and $freeze (see above) rimp2 also needs

$cbas file=auxbasis

cross reference for the file specifying the auxiliary basis as referenced in $atoms. We strongly recommend using auxbasis sets optimized for the corresponding MO basis sets.

Reasonable settings for these keywords may be generated by the tool Rimp2prep. Moreover you may specify by hand:

$tmpdir /work/thisjob

specification of directory for scratch files; by default files are written to the working directory; works also with capital letters (for consistency with ricc2).

$c1algorithm

avoids symmetry gymnastics in case of C₁-symmetry, rather for debugging

$cbasopt

enforces calculation of

$${\frac{{-\vert<ij\vert\vert ab>_{(exact)}-<ij\vert\vert ab>_{(RI)}\vert^2}}{{(\epsilon(i)+\epsilon(j)-\epsilon(a)-\epsilon(b))}}}$$

necessary for characterisation of auxiliary basis set quality and for auxiliary basis optimizations; works only for C₁-symmetry.
Note: all integrals are kept in memory, so this is for atoms and small molecules only.

$tplot

Enforces plotting of five largest t-amplitudes as well es five largest norms of t-amplitudes for fixed pair of occupied orbitals ij. By additional integer this number may be changed.

$mp2occ

Enforces plotting of all eigenvalues of the MP2 density matrix.