The pseudo-lattice(PL) method has been reformulated for ab initio self-consistent-field(SCF) calculations. The translational symmetries of infinite systems have been applied to the finite model chain by manipulating all the intramolecular and intermolecular Fock matrices. The nuclear repulsion energy has been corrected accordingly. The method has been tested for the linear chain of lithium hydride under the constraint of equidistance between all neighboring lithium and hydrogen atoms. The calculated results of the infinite chain have been compared with those of finite chains of lithium hydride under the same geometric constraint. The equilibrium geometries, band structures, intermolecular stabilization energies, and potential curves have been studied. It has been found that the infinite systems cannot be described by considering only first nearest neighbor interactions, and the intermolecular interactions must be considered at least up to third nearest neighbors in order to obtain accurate value of force constant of infinite systems. We can conclude from band structures of infinite chains that the boundary effect of the finite model chain is effectively removed by the PL method. In addition, we have investigated about the points of similarities and differences between lithium and hydrogen bonds which are known as good objectives for studying intermolecular interactions of electron donor-acceptor type. SCF and post SCF methods were employed to study the equilibrium structures, energies, and charge transfer appearences. The structures of lithium bonded complexes were observed to be quite linear. Accordingly, dipole moments of lithium bonded complexes were found to be increased. Lithium atoms in lithium bonded complexes were more shared by two groups of both directions than hydrogen atoms in hydrogen bonded complexes. Intermolecular interaction energies of lithium bonded complexes were found to be much greater than those of hydrogen bonded complexes. The direction of charge transfer were found to be same in both types of interaction. However, the electron density differences at the linking atoms were found to be opposite in sign atoms in the two types of bond. The intermolecular interaction energies of the lithium bonded complexes were less affected by the variation of the electron donor molecules and also by the substituents of lithium compounds.
가상격자 방법을 비근사 분자 궤도 함수론 계산에 사용될 수 있도록 재고안하였다. 분자와 분자간의 포크 행렬들을 조절하므로써 무한계의 이동 대칭성을 유한한 모델 사슬에 적용하여 표현시켰다. 그에 맞추어 핵간의 반발에너지를 수정하였다. 이와같이 재고안된 가상격자 방법을 수산화리튬의 곧은 사슬에 적용시켜 계산해 보았다. 평행 구조, 에너지 밴드 구조, 분자간의 안정화에너지, 그리고 포텐샬 함수 등에 관해 살펴보았다. 수소 결합과 비슷한 전자 주개-받개형태의 분자간 결합인 리튬결합에 관하여 연구했다. 리튬결합에 의한 여러가지 분자 집합체들의 평형 구조, 에너지, 그리고 전자밀도 변화에 관하여 분자 궤도 함수를 이용하여 연구하고, 또한 전자 상호 작용 효과를 고려한 분자 궤도 함수로 연구하여 이들을 서로 비교, 분석 하였다.
