Development of minimized mixing molecular orbital method for designing organic ferromagnets

Abstract

Predicting the high spin stability of organic radicals correctly for designing organic ferromagnets remains a significant challenge. We have developed a method with an index (L(min)) for predicting the high spin stability of conjugated organic radicals at the restricted open-shell Hartree-Fock level. Unitary transformations were performed for localizing the coefficients of nonbonding molecular orbitals, and subsequently the localized coefficients were used to calculate L(min) that indicates the high spin stability of conjugated organic radicals. This method can be combined with the elongation method to treat huge high spin open-shell systems. Thus, this method is useful for designing organic ferromagnets.

Quantum‐mechanical condensed matter simulations with CRYSTAL

“…As a matter of fact, the ROHF implementation in the CRYSTAL program became obsolete a few years ago and was no longer available in the latest versions of the code. However, in recent years, there has been a renewed interest in ROHF solutions, mainly as an improved starting point for post-HF treatments (Eriksen, Matthews, Jørgensen, & Gauss, 2016;Ferré, Guihéry, & Malrieu, 2015;Green, Nakata, Fedorov, & Slipchenko, 2016;Jian et al, 2016;Li, Baum, & Goldberger, 2016;FIGURE 10 Graphical representation of four point-defects in diamond: (a) the h100i split self-interstitial (in red); (b) the VI 1 defect where a vacancy and a selfinterstitial are first neighbors; (c) the VI S 2 defect where a vacancy is a secondneighbor of a self-interstitial with all C-C single bonds, and (d) the VI D 2 defect where a vacancy is a second-neighbor of a selfinterstitial with one C-C double bond (in green) Tran & Tran, 2016;Zhu & Aoki, 2015), which motivated us to restore the ROHF functionality in the program. A parallel implementation of ROHF has also been devised.…”

Elongation method for electronic structure calculations of random DNA sequences

“…[36] If we treat these properties with the corresponding DNA sequence in the database, we can easily identify relationships among the sequence, electronic structures, and properties/functions. These relationships, in turn, can contribute toward realizing high-level drug/material designs.…”

“…In addition to these examples, the ELG method provides information such as about the nonlinear optical property, [25] solvation energy, [25] and ferromagnetic property. [36] If we treat these properties with the corresponding DNA sequence in the database, we can easily identify relationships among the sequence, electronic structures, and properties/functions. These relationships, in turn, can contribute toward realizing high-level drug/material designs.…”

Magnetic gaps in organic tri-radicals: From a simple model to accurate estimates

“…Experimentally, these species, mostly based on nitroxide, nitronyl nitroxide and verdazyl units, can be managed without an excessive burden, whereas their relatively small dimensions allow for accurate and reliable computational investigations (besides the already cited work and references therein, some further references can be found in [38][39][40][41][42][43][44][45][46][47][48]).…”