PY-Nodes: An ab-initio python code for searching nodes in a material using Nelder-Mead's simplex approach

Pandey, Vivek; Pandey, Sudhir K.

doi:10.1016/j.cpc.2022.108570

Cited by 4 publications

(2 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For both TaAs and TaP, the self-consistent ground state energy calculations are performed over a k-mesh size of 10 × 10 × 10 with the charge convergence limit set to 10 −10 Rydberg. Using these ground state structures, the nodes-finding calculations are carried out via PY-Nodes code [32]. This code is based on Nelder-Mead's function minimization method.…”

Section: Computational Detailsmentioning

confidence: 99%

“…Any such attempts require the accurate finding of band-touching points in terms of their coordinates and energy. To ensure this, here we have used PY-Nodes code which is efficient in finding nodes using the first-principle approach [32]. This study clearly establishes out that each nodal-ring is composed of two arcs out of which one is the nodal-arc and other can be obtained from symmetry operations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Existence of nodal-arc and its evolution into Weyl-nodes in the presence of spin-orbit coupling in TaAs & TaP

Pandey

2023

J. Phys.: Condens. Matter

Self Cite

View full text Add to dashboard Cite

In this work, we report the existence of nodal-arc, which acts as the building block of all the nodal-rings in TaAs & TaP. This nodal-arc is found to be capable of generating all the nodal-rings in these materials upon the application of space-group symmetry operations including time-reversal symmetry. The arcs are obtained to be dispersive with the energy spread of ∼109 (∼204) meV in TaAs (TaP). Also, the orbitals leading to bands-inversion and thus the formation of nodal-arcs are found to be Ta-5d & As-4p (P-3p) in TaAs (TaP). The area of nodal-rings is found to be highly sensitive to the change in hybridization-strength, where the increase in hybridization-strength leads to the decrease in the area of nodal-rings. In the presence of spin-orbit coupling (SOC), all the points on these arcs get gaped-up and two pairs of Weyl-nodes are found to evolve from them. Out of the two pair, one is found to be situated close to the joining point of the two arcs forming a ring. This causes the evolution of each nodal-ring into three pairs of Weyl-nodes. The coordinates of these Weyl-nodes are found to be robust to the increase in SOC-strength from ∼ 0.7-3.5 eV. All the results are obtained at the ﬁrst-principle level. This work provides a clear picture of the existence of nodal-arc due to accidental degeneracy and its evolution into Weyl-nodes under the eﬀect of SOC.

show abstract

Section: Computational Detailsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Existence of nodal-arc and its evolution into Weyl-nodes in the presence of spin-orbit coupling in TaAs & TaP

Pandey

2023

J. Phys.: Condens. Matter

Self Cite

View full text Add to dashboard Cite

show abstract

PH-NODE: A DFPT and finite displacement supercell based python code for searching nodes in topological phononic materials

Pandey,

Pandey

2024

Computer Physics Communications

View full text Add to dashboard Cite

Hybrid beluga whale optimization algorithm with multi-strategy for functions and engineering optimization problems

Huang,

2024

J Big Data

View full text Add to dashboard Cite

Beluga Whale Optimization (BWO) is a new metaheuristic algorithm that simulates the social behaviors of beluga whales swimming, foraging, and whale falling. Compared with other optimization algorithms, BWO shows certain advantages in solving unimodal and multimodal optimization problems. However, the convergence speed and optimization performance of BWO still have some performance deficiencies when solving complex multidimensional problems. Therefore, this paper proposes a hybrid BWO method called HBWO combining Quasi-oppositional based learning (QOBL), adaptive and spiral predation strategy, and Nelder-Mead simplex search method (NM). Firstly, in the initialization phase, the QOBL strategy is introduced. This strategy reconstructs the initial spatial position of the population by pairwise comparisons to obtain a more prosperous and higher quality initial population. Subsequently, an adaptive and spiral predation strategy is designed in the exploration and exploitation phases. The strategy first learns the optimal individual positions in some dimensions through adaptive learning to avoid the loss of local optimality. At the same time, a spiral movement method motivated by a cosine factor is introduced to maintain some balance between exploration and exploitation. Finally, the NM simplex search method is added. It corrects individual positions through multiple scaling methods to improve the optimal search speed more accurately and efficiently. The performance of HBWO is verified utilizing the CEC2017 and CEC2019 test functions. Meanwhile, the superiority of HBWO is verified by utilizing six engineering design examples. The experimental results show that HBWO has higher feasibility and effectiveness in solving practical problems than BWO and other optimization methods.

show abstract

PY-Nodes: An ab-initio python code for searching nodes in a material using Nelder-Mead's simplex approach

Cited by 4 publications

References 41 publications

Existence of nodal-arc and its evolution into Weyl-nodes in the presence of spin-orbit coupling in TaAs & TaP

Existence of nodal-arc and its evolution into Weyl-nodes in the presence of spin-orbit coupling in TaAs & TaP

PH-NODE: A DFPT and finite displacement supercell based python code for searching nodes in topological phononic materials

Hybrid beluga whale optimization algorithm with multi-strategy for functions and engineering optimization problems

Contact Info

Product

Resources

About