c20 JWBS043-Rogers September 13, 2010 11:29 Printer Name: Yet to Come
330 QUANTUM MOLECULAR MODELING# sto-2gH2 molecule01
H
H1r
variables
r=0.7
FILE 20.6 (Input) A GAUSSIAN input file for H 2 .Thefileisinz-matrix format.systems: atom and molecule. Cancellation of error is often helpful but cannot be relied
upon. (Bear in mind that there is some uncertainty in the experimental value as well.)20.8.1 GAMESS
GAMESS (General Atomic and Molecular Energy Structure System) is a molecular
orbital program intended for general and academic use as open source software. The
authors do not charge for this program, but the user may not sell it to anyone else.
GAMESS gives the STO-2G energy calculated from input File 20.7. The geometry
of the molecule is given in Cartesian coordinates. Only one nonzero coordinate is
necessary to designate the geometry of a diatomic linear molecule. The bond length
is 0.7A (estimated). ̊
Translating File 20.7, each statement begins with $ and ends with $END. The
statement may occupy more than one line. The $CONTROL statement specifies the
SCFTYPe as RHF and the COORDinates as CARTesian $END. The $BASIS set is
a Gaussian BASIS, which is STO and contains a Number of GAUSSians equal to
2 $END. The $DATA set follows with an identifierHydrogenfor the human reader,
the symmetry Dn1, and the coordinates in Cartesian format $END.
The single entry 0.7A for the bond length is an element in the 2 ̊ ×3matrixof
locations in Cartesian space using three components for each atom. One atom is
placed at the origin and the other is placed on thexaxis at a distance of 0.7.$CONTRL SCFTYP=RHF COORD=CART $END
$BASIS GBASIS=STO NGAUSS=2 $END
$DATA
Hydrogen
Dn 1
H 1.0 0.0 0.0 0.0
H 1.0 0.7 0.0 0.0
$END
FILE 20.7 (Input) GAMESS file for hydrogen molecule. The SCF calculation is RHF, the
coordinate system is Cartesian and the stored basis set is STO-2G. The symmetry space group
is Dn 1, the charge on each hydrogen atom is 1.0, and the bond length is 0.7A. ̊