The charge-density distribution in various phases of ice is used to explore the information that can be obtained about the preferred directions of motion of atoms so as to investigate the possibility of the creation of more efficient and computationally cost-effective dynamical matrices. PACS Nos.: 63.20Dj, 31.90+s, 71.10-w
The electronic structure and sodium diffusion in Na4-xKxMg(MoO4)3 with an alluadite structure have been investigated by ab initio methods. It was found that this molybdate is an insulator with a band gap of 3.5 eV for x = 0.25. The most probable positions of potassium in the sodium sublattice have been determined, and the preferred pathways for sodium migration have been established. It has been shown that the barriers to sodium diffusion in Na4-xKxMg(MoO4)3 significantly depend on the composition, position of potassium, and migration path. The introduction of potassium leads to a significant decrease in the barriers to both one-dimensional (1D) and two-dimensional (2D) sodium diffusion. However, the presence of potassium in 1D channels can hinder the rapid migration of sodium, and a sharp increase in conductivity occurs only at high temperatures due to the order-disorder transition.
The first four states of the CH2 molecule ([Formula: see text]3B1, ã1 A1, [Formula: see text]1A1, and [Formula: see text]1A1) are examined using state-of-the-art ab initio methods and basis sets. The construction of potential energy curves with respect to the C + H2 and CH + H channels provides significant clues to understanding the geometric and electronic structure of the above states. All of our numerical findings are in excellent agreement with the existing experimental data. Key words: CH2, MRCI, potential curves, vbL icons.
Description of the Electronic Structure of Organic Chemicals Using Semiempirical and ab initio Methods for Development of Toxicological QSARs.