In this work, the required algebra to employ resolution of identity approximation within Piris Natural Orbital Functional (PNOF) is developed, leading an implementation named DoNOF-RI. The arithmetic scaling reduced from fifth-order fourth-order, and memory fourth-order third-order, allowing significant computational time savings. After DoNOF-RI calculation has fully converged, a restart with f...

Abstract NMR as a routine analytical method provides important three‐dimensional structure information of compounds in solution. Here we apply the recently released CRENSO computational workflow for automated generation conformer ensembles to quantum mechanical calculation 13 C‐NMR spectra series flexible cycloalkanes up C 20 H 40 . We evaluate computed chemical shifts comparison with correspon...

The efficient depolymerization and hydrodeoxygenation of enzymatic hydrolysis lignin are achieved in cyclohexane solvents over a gamma-alumina supported nickel molybdenum alloy catalyst single step. Under initial 3 MPa hydrogen at 320 °C, the highest overall cycloalkane yield 104.4 mg/g with 44.4 wt% selectivity ethyl-cyclohexane was obtained. reaction atmosphere temperature have significant ef...

Group Contribution Methods (GCMs) of Marrero & Gani (M G), Constantinou (C G) and Lydersen (LYD) were employed in the prediction some critical thermophysical properties(TPPs), namely; temperature (Tc), pressure (Pc), volume (Vc), boiling (Tb) melting (Tm), for various cycloalkanes. The predicted properties compared with available experimental data. Experimental data T m unfortunately very s...

This work reports a theoretical study of the gas-phase unimolecular decomposition of cyclobutane, cyclopentane and cyclohexane by means of quantum chemical calculations. A biradical mechanism has been envisaged for each cycloalkane, and the main routes for the decomposition of the biradicals formed have been investigated at the CBS-QB3 level of theory. Thermochemical data(DeltaHf(o), S(o), Cp(o...

The rate constants of the H-abstraction reactions from cyclopropane by H, O (3P), Cl (P3/2), and OH radicals have been calculated over the temperature range of 250−2500 K using two different levels of theory. Calculations of optimized geometrical parameters and vibrational frequencies are performed using the MP2 method combined with the cc-pVTZ basis set and the 6–311++G(d,p) basis set. Single-...

pyrolysis of low density polyethylene (ldpe) by equilibrium fluid catalytic cracking (fcc) was studied in a stirred reactor under different process parameters. in this work, the effect of process parameters such as degradation temperature (420-510°c), catalyst/polymer ratio (0-60%), carrier gas type (h2, n2, ethylene, propylene, ar and he), residence time and agitator speed (0-300 rpm) on the c...