the results of mndo, am1 and pm3 semi-empirical calculations and hf/6-31g*, mp/6-31g*, mp2/6-311+g**, and b3lyp/6-311g** and qcisd/6-31g* ab initio methods for angle strain and conjugation effects in twist-boat, boat, and half-chair geometries of (z,z,z)-cycloocta-1,3,5-triene indicate that all methods, except pm3, predict wrong ordering of the conformations.

The semiempirical theories of mixtures developed by van Laar, Margules, Scatchard-Hamer, Wilson and Renon and Prausnitz are used to study the concentration fluctuations of binary liquid alloys formed among the alkali metals. Examination of the fitting capabilities of these theories leads to the conclusion that those of van Laar, Scatchard-Hamer and Renon and Prausnitz are appropriate both when ...

A semiempirical approach for calculating the bulk and surface stress is developed and presented in this work. It is based on the tight-binding method with Chadi’s total energy model. A strained system is treated as a perturbation of an unstrained system; the corresponding stress can be calculated by the resolvent Green function method. This approach is applied to an arsenic terminated Si(001)23...

The present research studies and compares the effect of participating in team sports (soccer and volleyball) and individual sports (table tennis and badminton) on depression among high school students of Khoramdareh City in the period of 2006-2007. Research method is semi-empirical and the population of the research includes 1300 high school students of which 100 students with depression (rangi...

The phenomenon of soil liquefaction can be an induced effect earthquake shaking where the saturated loses some or all its bearing capacity and stiffness. Likewise, increase water pressure in pores under seismic wave causes a decrease shear strength. As result, becomes liquefied susceptible to producing permanent deformations. is generally unpredictable, neglecting it influence stability structu...