Massage Keyword
Last Update: 12/31/2000

The Massage keyword requests that the molecule specification and basis set data be modified after it is generated. The Massage keyword thus makes it possible to add additional uncontracted basis functions to a standard basis set. Common polarization or diffuse functions can be added in this way to standard basis sets for which these functions are not internally defined. For example, diffuse functions could be added to the 3-21G basis set to form 3-21+G. Similarly, polarization functions might be added to 6-311G to form a 6-311G(5d3f) basis, which is larger than the largest internally stored 6-311G-based basis set, 6-311G(3d1f).

The standard basis functions are assigned to atoms before Massage alterations take place, while the number of electrons is computed from the atomic numbers after the modifications.

Calculations with massaged basis set data cannot generate archive entries, and do not take advantage of molecular symmetry. Some of this functionality of Massage has been superceded by the ExtraBasis keyword. Point charge may also be specified for single point energy calculations using Charge.

Massage may also be used for counterpoise calculations and BSSE (see the examples).

center, func, exp, [c_X , c_Y , c_Z ]

where center is the center number (numbering follows the ordering of the molecule specification section), func is a code indicating the type of modification (see below), exp is the exponent of Gaussian or new nuclear charge (a value of 0 says to add a ghost atom), and c_X ,c_Y ,c_Z are the coordinates of the point charge in Angstroms when func is -1 (see below). A blank line terminates this input section.

func can take on these values:
0 orNuc Change the nuclear charge.
1 or SP Add an SP shell.
2 or D Add a D shell.
3 or P Add a P shell.
4 orS Add an S shell.
5 or F Add an F shell.
-1 or Ch Add a point charge.

Note that this keyword is not affected by the setting of the Units keyword, and its input is always interpreted as Angstroms.

Charge, ExtraBasis, Gen

Adding Point Charges. The following input file adds point charges to a calculation on water using the Massage keyword:

# RHF/6-31G(d) Massage Test

Water with point charges

0 1
O -0.464  0.177  0.0
H -0.464  1.137  0.0
H  0.441 -0.143  0.0

0 ch 2.0 1.0  1.0 1.0
0 ch 2.5 1.0 -1.0 1.0

Adding Basis Functions. The following input adds functions to the D95 basis set (in order to reproduce a calculation from the literature that used a non-standard basis set):

# RQCISD(Full)/D95 Freq=Numer Massage Test

H2O Frequencies at QCISD(Full)/DZP

0 1
O
H 1 R
H 1 R 2 A

R=0.961882
A=104.612551

1 D 0.85
2 P 1.0
3 P 1.0 

Computing Counterpoise Corrections. The following input file performs a portion of a counterpoise calculation, removing the HF molecule but leaving its basis functions (as has been repeatedly shown [285-286], counterpoise corrections provide only a crude estimate and not an upper bound on the error). Note that the dummy atom is not included in the numbering of the centers.

# HF/6-31G* Massage Test

HF + H2O interaction energy: HF removed

0 1
X
H 1 1.0
F 2 rHF 1 90.0
O 2 rHO 1 90.0 3 180.0
H 4 rOH 2 aHOH 1  90.0
H 4 rOH 2 aHOH 5 180.0

rHF 0.9203
rHO 1.8086
rOH 0.94
aHOH 126.4442

1 Nuc 0.0
2 Nuc 0.0

If a checkpoint file is saved after this calculation, the structure within it will have the ghost atoms rather than the atoms specified in the input, so it is best to start from a copy of the checkpoint file if you want to preserve the original data.

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