for better understanding of conformational stability of the dipeptide model hco—gly—l—leu—nh2,ab initio and dft computations at hf/6-31g(4 6-311++g(d,p) and b3lyp/6-31g(d) levels oftheory were carried out. geometry optimization of the dipeptide within the leucine (leu) side chainangles (x2 ,x2) resulted in three stable conformations as followings: anti-anti, the most stable one,(xi = 180°, x2 =...

bcn compounds have been researched theoretically and experimentally widely. in this paper, weintroduce the theoretical prediction of ternary b-c-n compounds. nmr spectroscopy was employedextensively to study these ternary nanostructures. we discuss the utilization of chemical shiftinformation as well as ab initio calculations of nuclear shielding for h20134c9n4 structuredetermination. we calcul...

highly crystalline and pure lithium metasilicate (li2sio3) and lithium disilicate (li2si2o5) nanomaterials were synthesized by hydrothermal method and characterized by pxrd technique. the changes in the morphology and particle size of the synthesized nanomaterials with reaction time were investigated using sem technique. the uv-vis and photoluminescence spectra of the compounds were studied. th...

this paper investigates the radiative absorptivity of a spherical cavity by using monte carlo techniques. several parameters such as the angle of incoming radiation which inters the cavity for both diffuse wall cavity and specular wall cavity has been  investigated. the absorptivity of a spherical cavity has been calculated and compared with the exact values when the angle of incoming radiation...

‎In this work‎, ‎a regular polygon with $n$ sides is described by a periodic (circular) sequence with period $n$‎. ‎Each element of the sequence represents a vertex of the polygon‎. ‎Each symmetry of the polygon is the rotation of the polygon around the center-point and/or flipping around a symmetry axis‎. ‎Here each symmetry is considered as a system that takes an input circular sequence and g...

Spin and spatial tensor manipulations are frequently required to describe the theory of NMR experiments. A Mathematica package is presented here, which provides some of the most common functions for these calculations. Examples are the calculation of matrix representations of operators, commutators, projections, rotations, Redfield matrix elements, matrix decomposition into basis operators, cha...

Numerical techniques for discretization of velocity space in continuum kinetic calculations are described. An efficient spectral collocation method is developed for the speed coordinate – the radius in velocity space – employing a novel set of non-classical orthogonal polynomials. For problems in which Fokker-Planck collisions are included, a common situation in plasma physics, a procedure is d...