Electro-optical effect of the nCOOCB liquid crystal molecules under the terahertz frequency range: A theoretical approach

The homologous series of 4-cyano-4'-phenyl-phenol-alkanoates (nCOOCB) was studied under the influence of terahertz (THz) frequency range. The nCOOCB series has a re-entrant nematic phase, which is suitable for electro-optical properties under the THz frequency. The birefringence and order parameter expresses the twisting of the nematic phase at the higher frequency range. The director angle has fluctuated at a higher frequency range. The refractive index has remained constant at a higher frequency. The ionisation potential, electron affinity and Homo-Lumo energy gap continuously decrease with an extension of alkyl chain length; however, the dipole moment increases. The Homo-Lumo energy bandgap is reciprocal to the dipole moment.

What Do We Learn from the Classical Turning Surface of the Kohn-Sham Potential as Electron Number Is Varied Continuously?

The classical turning radius Rt of an atom can be defined as the radius where the KS potential is equal to the negative ionisation potential of the atom, i.e. where v_s(R_t)=\epsilon_h. It was recently shown [P.N.A.S. 115, E11578 (2018)] to yield chemically relevant bonding distances, in line with known empirical values. In this work we show that extension of the concept to non-integer electron number yields additional information about atomic systems, and can be used to detect the difficulty of adding or subtracting electrons. Notably, it reflects the ease of bonding in open p-shells, and its greater difficulty in open s-shells. The latter manifests in significant discontinuities in the turning radius as the electron number changes the principal quantum number of the outermost electronic shell (e.g. going from Na to Na^{2+}). We then show that a non-integer picture is required to correctly interpret bonding and dissociation in H_2^+. Results are consistent when properties are calculated exactly, or via an appropriate approximation. They can be interpreted in the context of conceptual density functional theory.

What Do We Learn from the Classical Turning Surface of the Kohn-Sham Potential as Electron Number Is Varied Continuously?

The classical turning radius Rt of an atom can be defined as the radius where the KS potential is equal to the negative ionisation potential of the atom, i.e. where v_s(R_t)=\epsilon_h. It was recently shown [P.N.A.S. 115, E11578 (2018)] to yield chemically relevant bonding distances, in line with known empirical values. In this work we show that extension of the concept to non-integer electron number yields additional information about atomic systems, and can be used to detect the difficulty of adding or subtracting electrons. Notably, it reflects the ease of bonding in open p-shells, and its greater difficulty in open s-shells. The latter manifests in significant discontinuities in the turning radius as the electron number changes the principal quantum number of the outermost electronic shell (e.g. going from Na to Na^{2+}). We then show that a non-integer picture is required to correctly interpret bonding and dissociation in H_2^+. Results are consistent when properties are calculated exactly, or via an appropriate approximation. They can be interpreted in the context of conceptual density functional theory.

What Do We Learn from the Classical Turning Surface of the Kohn-Sham Potential as Electron Number Is Varied Continuously?

The classical turning radius Rt of an atom can be defined as the radius where the KS potential is equal to the negative ionisation potential of the atom, i.e. where v_s(R_t)=\epsilon_h. It was recently shown [P.N.A.S. 115, E11578 (2018)] to yield chemically relevant bonding distances, in line with known empirical values. In this work we show that extension of the concept to non-integer electron number yields additional information about atomic systems, and can be used to detect the difficulty of adding or subtracting electrons. Notably, it reflects the ease of bonding in open p-shells, and its greater difficulty in open s-shells. The latter manifests in significant discontinuities in the turning radius as the electron number changes the principal quantum number of the outermost electronic shell (e.g. going from Na to Na^{2+}). We then show that a non-integer picture is required to correctly interpret bonding and dissociation in H_2^+. Results are consistent when properties are calculated exactly, or via an appropriate approximation. They can be interpreted in the context of conceptual density functional theory.

Plasma processes to detect fluorine with ICPMS/MS as [M–F]+: an argument for building a negative mode ICPMS/MS

The paper describes that the 2nd ionisation potential and the difference in bond energy of a metal to fluorine bond and of a metal to oxygen bond are the most important parameters to form a metal fluoride ion for the detection of fluorine in ICPMS/MS.

Cs1−xRbxSnI3 light harvesting semiconductors for perovskite photovoltaics

Partial substitution of Cs with Rb in CsSnI3 perovskite imparts useful increases in ionisation potential for photovoltaic applications.

Structural, Spectroscopic, and Energetic Parameters of Diatomic Molecules Having Astrophysical Importance

This research investigates molecular parameters such as equilibrium structure, dipole moment, rotational constant, harmonic frequency, adiabatic electron affinity, atomisation energy, and ionisation potential of some identified diatomic molecules in interstellar/circumstellar medium. A theoretical understanding of the molecular properties of the investigated molecules is obtained using the popular B3LYP hybrid density functional with four basis sets: 6-311++G(2df,2pd), 6-311++G(3df,3pd), cc-pVTZ, and aug-cc-pVTZ. The computed data conform very well with available experimental and theoretical results. The accuracy of the B3LYP functional on the studied molecular systems are ±0.006 Å for the bond length, ±0.044 D for the dipole moment, ±0.854 GHz for the rotational constant, ±59 cm−1 for the harmonic frequency, ±2.03 kcal/mol for the electron affinity, ±4.74 kcal/mol for atomisation energy, and ±3.19 kcal/mol for ionisation potential.