The following is a typical MOLPRO input file for a somewhat more demanding calculation, taking a UCCSD(T)/RHF/631+G(d)//UB3LYP/augccpVDZ sp on the acetic acid1yl radical as an example:
***,test2
memory,128,M
GEOMETRY
UNITS=ANGSTROM
C,0,0.1919268647,0.2072859957,1.3789010049
C,0,0.0967723243,0.0274582322,0.04410443
O,0,1.0336868467,0.3455167,0.7638314734
O,0,1.1693183348,0.142245749,0.5287556409
H,0,1.1272934512,0.0363554656,1.4815911115
H,0,1.1633382061,0.0952554144,1.8527029152
H,0,0.6831879848,0.4883010784,1.9608056609
ENDG
BASIS=631+G*
int,cart;
{rhf;
wf,31,1,1;}
uccsd(t);


The first line of the input file:
***,test2
specifies nothing more than the name of this job (here: test2). The following line:
memory,128,M
defines the amount of dynamic memory available for this calculation to be 128 million words, corresponding to 1 GB of main memory. The geometry definition follows in the next block mof input:
GEOMETRY
UNITS=ANGSTROM
C,0,0.1919268647,0.2072859957,1.3789010049
C,0,0.0967723243,0.0274582322,0.04410443
O,0,1.0336868467,0.3455167,0.7638314734
O,0,1.1693183348,0.142245749,0.5287556409
H,0,1.1272934512,0.0363554656,1.4815911115
H,0,1.1633382061,0.0952554144,1.8527029152
H,0,0.6831879848,0.4883010784,1.9608056609
ENDG
In this particular case the geometry is given in cartesian coordinates as dumped to the output file of a previous calculation with Gaussian.
The basis set to be used in the calculation is specified using the "BASIS=" keyword:
BASIS=631+G*
This is followed by selecting the integral calculation model. Since the subsequent CCSD(T) calculations will not work in direct mode, the "int" keyword is specified here to select conventional integral evaluation. The "cart" keyword selects six cartesian dtype polarization functions. This corresponds to the original definition of dtype polarization functions for Pople's 631G basis set. Most quantum chemistry program packages use 5 spherical dtype polarization functions by default.
int,cart;
Details of the SCF calculations are specified in the next two lines. The "rhf" keyword calls for a restricted openshell (ROHF) calculation. The following "wf" keyword defines the wavefunction to include 31 electrons, to be of symmetry 1, and to correspond to a doublet state. The total symmetry of the wavefunction of "1" corresponds to the first irreducible representation of the C1 point group (well, there is only one in this case). In most cases these keywords are sufficient to converge the system to the lowest electronic state of a given symmetry.
{rhf;
wf,31,1,1;}
Finally the coupled cluster program is called to perform an unrestricted CCSD(T) calculation on the closed shell (ROHF) reference determinant.
uccsd(t);
The last line of the input:

signals the program the end of the input file. Since all following input is ignored this is helpful to add some comments to the actual input file.