CAJ | 학술논문

采用不同方法、在不同基组水平上系统地对(NH3)2缔合体进行构型优化和结合能计算,并和实验值做详细比较.(1)对于弱氢键体系(NH3)2,B3LYP和HF计算结果不可靠;(2)适合(NH3)2体系的最好计算方案是MP2/6-311++G**(如果基组不低于6-31++G**水平,计算结果也可取),但是必须做BSSE校正.(3)基组中不加弥散函数只能得到一种环状构型,加入弥散函数可以得到两种构型.(4)对于弱相互作用体系,在选用计算方法和基组前应该做充分的方法验证.
채용불동방법、재불동기조수평상계통지대(NH3)2체합체진행구형우화화결합능계산,병화실험치주상세비교.(1)대우약경건체계(NH3)2,B3LYP화HF계산결과불가고;(2)괄합(NH3)2체계적최호계산방안시MP2/6-311++G**(여과기조불저우6-31++G**수평,계산결과야가취),단시필수주BSSE교정.(3)기조중불가미산함수지능득도일충배상구형,가입미산함수가이득도량충구형.(4)대우약상호작용체계,재선용계산방법화기조전응해주충분적방법험증.
Geometry optimization and calculation of binding energy of the system of (NH3)2 were carried out by different methods at different levels of basis set systematically, and all the computational structural parameters were compared with the experimental ones. Both B3LYP and HF are not suitable for the weak hydrogen bond system of (NH3)2. The best method is MP2/6-311++G**, and the BSSE must be corrected. Diffuse function plays an important role in the geometry optimization, i.e., there are two geometries of ring and line augmented with a diffuse function and only one geometry of ring otherwise. The binding energy of the ringy geometry is lower than that of the linear geometry. It is constructive that an elaborate comparison is necessary to make before any method or basis set is adopted for a weak interactional system.