Table of contents
MOLECULE input section specifies the molecular information: such as
geometry, (approxmiate) spin multiplicity, and charge. The
MOLECULE section is
a required section for all ChronusQ jobs.
||Signed Integer||Overall molecular charge (in electrons)||Yes||N/A|
||Unsigned Integer||Approximate spin multiplicity||No||0|
||Multiline String||Geometry specification from input file (in Angstroms)||Yes if
||String||Location of geometry specification (
GEOM keyword provides the specification for the position and identity of all atoms in the system. It is a multiline keyword, meaning it expects data to be provided as indented lines after the declaration. The data lines for the
GEOM keyword are in the format:
ATOMIC_SYMBOL POSITION_X POSITION_Y POSITION_Z
Currently, only cartesian coordinates in Angstroms are available. As an example, take this specification of the geometry of ammonia:
geom: N -0.00000 0.00000 0.00000 H 1.01733 -0.06831 -0.01031 H -0.31160 -0.66357 0.70776 H -0.31160 -0.38951 -0.89427
Note that the geometry must be indented relative to the
Location to retrieve geometry. Either
INPUTFILE (default) or
ChronusQ currently supports reading geometry specification from a Gaussian formatted checkpoint file. If this is desired, set
FCHK. You must also specify the formatted checkpoint file on the invocation of ChronusQ. (See Running ChronusQ)
INPUTFILE: Geometry specification in ChronusQ input file (see example below)
GEOMkeyword must also be specified.
FCHK: Geometry specification in fhck file from the Gaussian software package
GEOMkeyword will be ignored.
- Atoms are assumed to be the default isotope.
[Molecule] charge = 0 mult = 3 geom: O 0. 0. 0.608586 O 0. 0. -0.608586