Anchoring the potential energy surface of the nitrogen/water dimer, N-2 center dot center dot center dot H2O, with explicitly correlated coupled-cluster computations

作者：Ellington Thomas L; Tschumper Gregory S^*

来源：Computational and Theoretical Chemistry, 2013, 1021: 109-113.

DOI：10.1016/j.comptc.2013.06.035

• Nitrogen water dimer potential energy surface
• Harmonic vibrational frequencies
• CCSD(T) CBS limit
• Foreign continuum

Six different stationary points have been identified and characterized on the potential energy surface of N-2 center dot center dot center dot H2O (i.e., the non-covalent dimer formed between nitrogen and water). Optimized geometries and harmonic vibrational frequencies have been computed using the MP2 and CCSD(T) ab initio electronic structure methods in conjunction with a series of correlation consistent basis sets as large as aug-cc-pVQZ. In addition, explicitly correlated CCSD(T)-F12 single point energy computations in conjunction with basis sets as large as aug-cc-pV5Z have been used to estimate the relative energetics at the complete basis set (CBS) limit. Only one configuration corresponds to a minimum, a Cs structure with an N-2 center dot center dot center dot H2O interaction and an electronic dissociation energy of 1.22 kcal mo1-1 at the CCSD(T) CBS limit. CCSD(T) harmonic vibrational frequency computations indicate that the IR intensities of the OH stretching modes increase substantially when the dimer forms. Three transition states lie 0.51-0.61 kcal mol(-1) above the global minimum at the CCSD(T) CBS limit, which indicates that the barriers associated with rearrangement pathways are comparable to those for (H2O)2.

• 出版日期2013-10-1