MCP  MCP string MCP defines the global model core potentials. If absent, an allelectron calculation is assumed by default. 
atomic symbol
element symbol
global MCPS
basis set name
Thus, as in the case of ECPS, any MCPS definition for an atom can be overridden by the explicit assignment of the MCP using the atomic symbol. For example, in a system containing two copper atoms, e.g. linked to an organic ligand, the following MCPS definition,
MCPS (MCPLK) Cu (MCP17LK) Cu1 (RMCP17LK)
assigns the 17electron quasirelativistic MCP from Lovallo and Klobukowski [152,153] denoted by (RMCP17LK) to copper atom Cu1, the 17electron nonrelativistic MCP by the same authors, denoted by (MCP17LK), to other copper atoms, and the globally defined (MCPLK) nonrelativistic MCP to any atom of other types that is present in the ligand. The file MCPS contains the MCPs from Lovallo and Klobukowski [152,153] in the deMon2k format. Figure 9 shows the elements for which MCPS are available in the MCPS file.

Specifying only the keyword MCPS and not specifying the corresponding valence basis set leads to a situation in which the default allelectron DZVP basis set is used in combination with the specified model core potentials. Therefore it is handy to define the model core potential and the corresponding valence basis set at the same time with the keyword BASIS. The keyword MCPS should then be used only to define a model core potential different from the one automatically invoked by the specified basis set. In the following example
BASIS (MCPLK) MCPS Cu (MCP17LK) Cu1 (RMCP17LK)
the explicit specification of the model core potential by the MCPS keyword overrides the global model core potential invoked with the keyword BASIS. The model core potentials can also be specified in the input file using the format
MCPS SYMBOL Read ELECTRONS LS NLS N K EXPONENT COEFFICIENT : : EXPONENT COEFFICIENT N K F EXPONENT COEFFICIENT : : EXPONENT COEFFICIENT
Here SYMBOL can be an element or atomic symbol, ELECTRONS is an integer number specifying the number of valence electrons, LS is the number of local shells in the model potential, and NLS is the number of nonlocal (core) shells. All local shells are loaded first. For each local shell, N represents the radial power and K the degree of contraction. For nonlocal shells, N represents the principal quantum number, K is the degree of contraction, and F is the energy weightfactor of the nonlocal projector of this shell. The exponents and contraction coefficients are listed in free format under the MCP block definition line, one line for each Gaussian (EXPONENT and COEFFICIENT).