#! /bin/sh
# This is a small but important example to illustrate what goes into an accurate
# calculation of the 'true' bond energy of a molecule. The (ADF-specific)
# problem is that in a straightforward molecular calculation, the bond energy is
# computed as the energy difference between at the one hand the molecule, and at
# the other hand the isolated spherically symmetric spin-restricted atoms.
# This spherically symmetric spin-restricted reference (comparison) state is usually
# not the physical ground state of the reference system (isolated atoms) and
# hence the computed energy difference has no direct relation to experimental
# data. To account for the true atomic ground states, one has to add correction
# terms. Study this sample carefully to make sure that you fully understand the
# steps to take and consult the User's Guide for details. See also the this
# document for a discussion of multiplet states.
# See also the example, SD_Cr(NH3)6.
# The H2 case consists of a sequence of simple calculations to demonstrate the
# Unrestricted Fragments options.
# In the first part real spin-unrestricted fragments are used.
# In the second part simulate spin-unrestricted fragments are used.
# Unrestricted fragments
# ======================
# If one uses unrestricted fragments one needs to calculate the unrestricted
# H atom twice, one in which the 1s alpha orbital is occupied, and one in which
# the 1s beta orbital is occupied.
AMS_JOBNAME=H_A $AMSBIN/ams <