Castep is a fullfeatured materials modelling code based on a firstprinciples quantum mechanical description of electrons and nuclei. The new paradigm of gpu computing has brought together the high performance of a supercomputer, mixed with the form factor, affordability, and power efficiency of a desktop computer. We then provide a literature survey on noncollinear multiferroic perovskites. Here is a list of software codes that may be used to perform the sort of research of interest to the psik community. How can i solve convergence problems with vasp and large magnetic system. Spontaneous decays of magnetoelastic excitations in non. Antiferromagnets can be collinear or non collinear. I am running noncollinear calculations with lorbit2 or 12 to get the projections with the phase factor. The latter interaction results in the occurrence of metastable states corresponding to a noncollinear magnetic structure. Instead, the eigenstate of an atom is a spinor with a certain mixing of both spin up and down channels, and many quantities like the.
Within the dft framework, magnetism can either be neglected completely, be considered in a restricted collinear, nonspinorbitcoupled case, or include noncollinearity and spinorbit coupling. We present a realspace pseudopotential method for first principles calculations of noncollinear magnetic phenomena within density functional theory. Implementation of noncollinear spinconstrained dft calculations. The quantum espresso software distribution shobhana narasimhan, jncasr 4. First, we show ddec6 charge partitioning to assign net atomic charges corresponds to solving a series of 14 lagrangians in order. Vasp vasp stands for vienna abinitio simulation package performs abinitio quantummechanical molecular dynamics md using pseudopotentials and a plane wave basis set the code is written in fortran 90 with mpi support access to the code may be given by a request via the vasp website. Introduction to noncollinear spin quantumatk q2019. In the present paper an attempt is made to classify collinear and noncollinear by means of transformation properties of classical vectors heisenberglike models of magnetism, and spinors and bispinors as used within a nonrelativistic and a relativistic description of magnetism based on the local density functional approach. This can be ferromagnetic fm, where spins are aligned in parallel directions, antiferromagnetic afm, where the spins are antiparallel, or noncollinear, where the spins are not parallel and may be disordered. Learn how vasp s tight integration into the medea software environment enables easy access to comprehensive structural databases and advanced model.
Links to home pages are given where possible, together with a short description and some details about licensing. You then also have another spin direction which makes for example 60 deg. Electronic topological transition and noncollinear magnetism in compressed hcp co y. Noncollinear exactexchange kpar passively supported scgw0 damped all algo. Wien2k software package an augmented plane wave plus local orbital program for calculating crystal properties peter blaha karlheinz schwarz georg madsen dieter kvasnicka joachim luitz november 2001. We have studied the electronic, magnetic and linear phonon dispersion behavior of phosphorene monolayer using rst principle based ab initio method. How can i decide if magnetic calculation should be collinear or. The only change ive made is disable the dngxhalf and dngzhalf in.
Max hutchinson uofc vasp on gpus november 17, 2015 18 18. Highpressure synthesis of magnetic neodymium polyhydrides. Magnetooptic kerr effect and ferromagnetic resonance techniques were employed to investigate magnetic properties. The supercell size, kinetic energy cutoff, and brillouin zone sampling of the calculations were determined after extensive convergence analyses. See calculation setup and examples on the above site for more information. With such collinear functionals, the offdiagonal derivatives containing the magnetization densities along the x and y directions cannot be calculated since these components are neglected. I am doing a constrained noncollinear calculation using vasp 120 degree inplane antiferromagnetism. How to do a constrained noncollinear calculation using vasp. When a non collinear wavecar file is read, the spin is assumed to be parallel to saxis hence vasp will initially report a magnetic moment in the zdirection only. The vienna ab initio simulation package vasp is a computer program for atomic scale materials modelling, e. We discuss, in particular, the interplay between noncollinear magnetism and ferroelectric and antiferrodistortive distortions of the perovskite structure, and how this can promote magnetoelectric responses.
Noncollinear magnetism ncm with arbitrary onsite magnetic fields. You can have spins in one direction which is compensated by another spin in the opposite direction. The exchange interactions both between the rareearth re and transition metal sublattices and within the re sublattice play an important role in the model. Postnikov universit e metz magnetic systems june 2010 11 22.
I am interested in using vasp to do a non collinear magnetic calculation. Eriksson department of physics and astronomy, division of materials theory, uppsala university, box 516, se75120 uppsala, sweden received 27 august 2015. Winter school computational magnetism vasp tutorial c. An extensive list of properties can be calculated without relying on empirical. Eriksson1 1department of physics and astronomy, division of materials theory, uppsala university. Introduction to noncollinear magnetism and spinorbit. Spinors were included by georg kresse in the vasp code. So when should i do calculation with collinear or noncollinear tags. How can i solve convergence problems with vasp and large. Pressure and strain effects of hexagonal rareearth. One solution would be to use noncollinear exchangecorrelation functionals recently proposed for lda and gga functionals.
Detailed discussion is given in the supplementary note 1. How to do a constrained non collinear calculation using vasp. Highthroughput prediction of the groundstate collinear. Maggene uses total energy, calculated by vasp code20, as the. Program computing ddec atomic charges browse files at. Noncollinear magnetism calculations have been carried out by including the spinorbit coupling as implemented in vasp by hobbs et. It is important to realize that the familiar concept of spin as being either up or down and all derived quantities also being labeled by this quantum number does not work in a noncollinear dft calculation. How to do simple calculations with quantum espresso.
The most used software package for computational materials. Winter school computational magnetism 3mm vasp tutorial. The vienna ab initio simulation package vasp is an atomic scale materials modelling program for e. Gpu vasp will give 24x performance on moderate to large systems. Vasp is capable of reading wavecar and chgcar files from previous nonmagnetic or collinear calculations, it is however not possible to rotate the magnetic field locally on selected atoms. The second method also allows to read a preexisting wavecar file from a collinear or non collinear run, and to continue the calculation with a different spin orientation. It works for a broad range of periodic and nonperiodic materials with no magnetism, collinear magnetism, and noncollinear magnetism irrespective of the basis set type. The code required for the treatment of noncollinear magnetic structures was written by david hobbs. I have some confusions about how to do it correctly.
Gpaw is a densityfunctional theory dft python code based on the projectoraugmented wave paw method and the atomic simulation environment. Noncollinear magnetism marie curie fellows association. I am doing a constrained non collinear calculation using vasp 120 degree inplane antiferromagnetism. Introduction to noncollinear magnetism and spinorbit coupling in quantumespresso andrea dal corso sissa and democritos trieste italy. It uses the robust methods of a planewave basis set and pseudopotentials. The code required for the treatment of noncollinear magnetic structures was written by david hobbs, and spinorbit coupling was implemented by olivier lebacq and georg kresse. Specifically, for a 2d material to check the magnetization direction relative to the plane. Numerical calculations were performed by using the vasp software 24. Electronic topological transition and noncollinear. The main features and functionalities of the munich sprkkrpackage, as for example the spinpolonetep ordern electronic total energy package is a linearscaling code for quantummechanical calculations based on densityfunctional theory. This tutorial therefore provides a simple introduction to atkdft calculations with noncollinear spin densities.
Spontaneous decays of magnetoelastic excitations in noncollinear antiferromagnet. Noncollinear calculations and spin orbit coupling spinors were included by georg kresse in the vasp code. For more information on vasp please visit what is vasp 2 license and citing. Note that one can choose a nonprimitive unit cell e. In most magnetic materials, the arrangement of the atomic magnetizations.
Groundstatecalculation excitations non collinear magnetism in the elk code f. Are there examples of collinear and noncollinear magnetism. Ive recently recompiled vasp for noncollinear magnetism calculation. Electronic topological transition and non collinear magnetism in compressed hcp co y. Non collinear spin calculations with lorbit 2 or 12.
The program analyzes electron and spin density distributions generated by a quantum chemistry e. Abstract in this study, effects of pt spacer and co reference layers thickness in copt 6 ptco multilayer have been revealed to tailor magnetization directions in noncollinear configuration. Vasp is capable of reading wavecar and chgcar files from previous nonmagnetic or collinear calculations, it is however not possible to rotate the magnetic field locally on selected. Implementation of noncollinear spinconstrained dft calculations in siesta with a. Effects of spinorbit coupling and noncollinear magnetism were taken into account in the spinpolarized calculations. In vasp, how can i find the magnetic moment components due to orbital, spin and. A genetic evolution program for magnetic structure. I also tried to first use the non magnetic solution as a starting point, using. Phonons, elastic constants, internal strain tensors. A fast way from models to reliable results replay with updates in medea vasp. Noncollinear spin calculations with lorbit 2 or 12.
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