23.1 Expectation values for MP2


One-electron properties can be computed if an EXPEC card follows the MP2 card (the GEXPEC directive has no effect in this case). Properties are obtained as analytical energy derivatives with or without taking into account the orbital relaxation, which can be specified as

type=RELAX: Compute fully relaxed properties with taking into account the orbital relaxation (default). Nonrelaxed properties are also computed and printed. For MP2, this option is highly recommended.
type=NORELAX: Compute properties without taking into account the orbital relaxation.

Note that, in MP2, calculation of fully relaxed properties may be much more expensive than computing only the energy or properties without the orbital relaxation effect. The syntax for operators opname is explained in section 6.13. See also DM in section 23.3, and NATORB in section 23.4.

molpro@molpro.net 2019-06-16