Quantum Chemistry Calculated Intermolecular Interaction Database and Symmetry-Adapted Perturbation Theory Analysis of Molecular Dimers

• Main Authors: Yu-Ming Chang, 張育銘
• Other Authors: 趙聖德
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/k5cmkx

碩士 === 國立臺灣大學 === 應用力學研究所 === 106 === The first topic of this research is quantum chemistry calculated intermolecular interaction database. Due to the noncovalent interactions are importance in many areas of chemistry,biology,and material science. In the past decade, we have seen a great acceleration in the development of new quantum chemical methods, those new computational techniques that potentially improve the accuracy of result. As the value of all scientific models must ultimately be determined by comparison with experimental observations, ot would be ideal if the empirical models were based on experimental data. Unfortunately, in many cases, the computed quantity cannot be isolated in an experiment, and direct comparison is thus impossible. In such cases, it is necessary to establish a set of very accurate, well-characterized computational data that can be used to parametrize and validate empirical models. In order to create an ab initio force field database of benchmark interaction energies for noncovalent interactions systematically. The data set consists of 30 complexes dimers. The dimers we chosen so that they represent the motifs and functional groups most commonly, contain alkane, alkene, alkyne(dispersion dominated), alcohol, aldehyde, ketone, acid and amide complexs.We have calculated the intermolecular interaction energy of the dimers with second-order Møller-Plesset perturbation theory(MP2), and coupled cluster(CC) method, and the correction of the basis-set superposition error(BSSE) has been included. In the structure optimization and interaction energy calculations of dimers, we employed MP2 method with Dunning’s correlation consistent basis sets[cc-pVXZ (X=D,T,Q)and aug-cc-pVXZ, (X=D,T,Q)]. In addition, single-point coupled cluster with single and double and perturbative triple excitation (CCSD(T)) calculations were carried out to calibrate the MP2 interaction energy. On the other hand, the complete basis set limit(CBS) can be obtained by extrapolation of sevel basis-set were carried out to calibrate the CCSD(T) interaction energy. The relationship between the basis-set and CBS convergence is discussed. After the interaction energy database construction is completed, PSI4 software was utilized to apply SAPT method to decompose the intermolecular interaction into four parts, as electrostatic energy, induction energy, dispersion energy, exchange energy, to analyze the repulsion and attraction effect on stability of molecular dimer. Not only to obtain the composition of intermolecular forces, but we also wondering more detailed than the SAPT analysis to explore the four composition are interaction from which group of molecular dimer.