Midbond functions

Table 33.1 Components of the SAPT interaction energy of the water dimer for four intermolecular separations R, computed in the [5s3p3d2flglh/3s3pldlf ] basis taken from Ref. [103], containing the 3s2pldlf set of midbond functions. The angular coordinates are close to those of the global minimum configuration. All energies in kcal/mol...

Basis functions In the context of solutions of the electronic Schrodinger s equation for hydrogen-bonded system, this term refers to Gaussian functions of the form exp[-ar ], where r is the position vector, multiplied by powers of the coordinates x, y, and z. The basis functions are usually located at the nuclear positions and near the midpoint of the hydrogen bond (midbond functions). Linear combinations of such basis functions form molecular orbitals. 

Author s calculations for rj = r2 = 2.07 Uq HF method with aug-cc-pVTZ basis set plus midbond functions (BSSE corrected) MP2 method with aug-cc-pVTZ basis set plus midbond functions (BSSE corrected) MP2 method with aug-cc-pVQZ basis set plus midbond functions (BSSE corrected) CCSD(T) method with aug-cc-pVTZ basis set plus midbond functions (BSSE corrected) Modified model... 

The ab initio calculations were carried out at the CCSD(T) level of theory with aug-cc-pVTZ basis set augmented by midbond functions (for more details, see Ref. [31]). Then, the full 3D surface of each dipole moment component was represented as a sum of spherical harmonics multiplied by corresponding expansion coefficients and a cosine/sine function. 

Baranowska et reported a high-level investigation of the potential energy surface (PES) of the Ne-CO interaction. The calculations were performed at the CCSD(T) level of theory with the d-aug-cc-pVTZ basis set supplemented with 3s3p2dlflg midbond functions. The minimum of the PES corresponds to a nearly T-shaped structure with the Ne atom located at a distance of 3.383 A from CO and an angle of 79.4°. The interaction-induced electric dipole moment and polarizability was determined at the CCSD/d-aug-cc-pVTZ-33211 level of theory. In addition, the authors determined the dielectric and refractivity virial coeflicients and the pressure virial coeflicients of the CO-Ne complex. 

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