The History of Language Processor Technology in IBM

Abstract

The history of language processor technology in IBM is described in this paper. Most of the paper is devoted to compiler technology; interpreters, assemblers, and macro systems are discussed briefly. The emphasis is on scientific contributions and technological advances from a historical perspective. The synergistic relationship between theory and practice is a subtheme.

Analytical functional representation of quantum chemical potential energy curves and surfaces

“…Double rotor Potential energy surfaces (PES) were generated and analytic functions were fitted for the grids for propane [2], n-pentane [3], glycine diamide [4], alanine diamide [4] and valine diamid [4]. The accuracy of the fit improved with the complexity of the fitted functions.…”

“…During the last half century, the computer technology has improved a lot. For instance, in the 1960s, the third generations of computers have appeared 3 . These computers included integrated circuit and semiconductors.…”

“…This approximation allows that, to define molecules by a geometry structure determined by the nuclear positions. The Born-Oppenheimer 26 approximation gives a reasonable version of the many-body Hamiltonian [3]:…”

“…ϕHF=Âφ1(1)φ 2(2)φ 3 (3) ...φ n(n)=Do [4] where Do is the Slater determinant, φi are the spin-orbitals and  is the antisymmetrizer operator.…”

“…Molecules with rotating sp 3 ligand were studied as double rotors to generate the Potential Energy Surface (PES).…”