… that all languages bear different world outlooks, cultures, social values, and lifestyles whether they have a strong political, economic and social backgrounds or not. Since indigenous and endangered languages provide us hidden knowledge and education about history, culture, foo…

…and especially Jamil Tahir-Kheli for his own special way of mixing science with life. iv Abstract This thesis deals with the development of new methods for doing ab initio quantum mechanical calculations of electronic wavefunctions of large molecules and crystalline systems with …