Accurate Kr–CO interaction potential energy surface with vibrational coordinate dependence

The first three-dimensional interaction potential energy surface of the Kr–CO complex is developed using the single and double excitation coupled cluster theory with noniterative treatment of triple excitations [CCSD(T)]. Mixed basis sets, aug-cc-pVQZ for the C and O atom and aug-cc-pVQZ-PP for the Kr atom, with an additional (3s3p2d2f1g) set of midbond functions are used. We first fit the calculated single point energies to an analytic two-dimensional potential model at each of five fixed r co values. The five model potentials are then used to construct the three-dimensional potential energy surface by interpolating along ( r - r e ) using a fourth-order polynomial. Adopting the vibrationally averaged potential, we calculate the bound states. Compared with the previous work, the present work gives more accurate results along with the experimental data.