Unanswered Questions

127 questions with no upvoted or accepted answers
17
votes
0answers
67 views

Benchmark Timings of Machine Learning Potentials vs Molecular Mechanics Force Fields

Machine learning is an increasingly common tool for developing force fields for molecular dynamics simulations. It's not totally clear what should be considered a machine-learning potential, but let's ...
16
votes
0answers
186 views

How to set up a local server for iQmol on macOS?

I'm trying to set up iQmol as a tool to submit calculations to Q-Chem on our lab machines to make access to it easier for OChem students. Unfortunately, it is not working properly "from the box&...
15
votes
0answers
86 views

What are the recent developments of TDDFT to simulate the excited properties of materials?

The time-dependent density functional theory (TDDFT) and the many-body perturbation method (GW@BSE) are considered as the two most popular and successful methods to describe the excited-stated ...
15
votes
0answers
172 views

Promising functionals for transition metal chemistry

I'm looking to get your opinions on the most promising density functionals to use for thermochemistry and kinetics of transition metal complexes. However, as eloquently laid out by Tom Manz on this ...
15
votes
0answers
97 views

How to find the projected Hamiltonian for lowest flat-band in general?

In [1], starting with the bosonic Hamiltonian (Eqn. 1) for the dice lattice model with half flux density (with Ahronov-Bohm phases incorporated), \begin{equation} H=-t\sum_{\langle j,\mu\rangle}(a^\...
14
votes
0answers
95 views

What are the advantages of different point defects calculation tools?

As far as I know, there are mainly PyCDT, PyDEF, pylada and some part of pymatgen. As a new user to those tools, which one would be a good choice? pycdt: Python Charge Defects Toolkit (PyCDT) is a ...
13
votes
0answers
122 views

Is there a software that has implemented forces of TDDFT calculations for solids?

I'd like to investigate the structural relaxations of the excited state for periodic systems. BSE and TDDFT are two promising methods for this purpose. While there is a discussion on BSE Is there a ...
12
votes
0answers
72 views
+50

What are the recent developments of GW@BSE to simulate the excited properties of materials?

The time-dependent density functional theory (TDDFT) and the many-body perturbation theory (GW@BSE) methods are considered as the two most popular and successful methods to describe the excited-stated ...
12
votes
0answers
156 views

First order variation of the wave function of conduction states

The first order variation of the wave function $\Delta \psi_n$ is obtained by standard perturbation theory (Eq. 25 of ref 1): \begin{equation} (H_{SCF}-\epsilon_n)|\Delta \psi_n \rangle = -(\Delta V_{...
12
votes
0answers
96 views

Empirically determining thermostat damping factor

tl;dr Is there a way to determine an appropriate thermostat damping factor given a timestep size and a numerical integration method? I am computing a set of simulations in LAMMPS, using ReaxFF, ...
12
votes
0answers
89 views

Sample LAMMPS file for graphene growth on a metal surface

I am working with graphene growth on metal substrates. But I need some sample files to know if I am doing it in the right way because running multiple simulations in LAMMPS takes a lot of time. Can ...
11
votes
0answers
52 views

Why are Norm-conserving Pseudopotentials considered so important?

So I am aware that a norm-conserving pseudopotential enforces the conditions that: Inside the cut-off radius, the norm of each pseudo-wavefunction is identical to its corresponding all-electron ...
11
votes
0answers
71 views

Recent developments in QM/MM for Molecular Dynamics

I am looking for new QM/MM methodologies which have recently developed and implemented into MD packages. Any applications or molecular systems studies with these methods can be used as an example as ...
11
votes
0answers
100 views

Why linear response is absent in a non-centrosymmetric system with time reversal symmetry?

In this paper, it is mentioned that a non-centrosymmetric system with time-reversal symmetry doesn't have a linear response. It is actually a consequence of the Onsager reciprocal theorem. But I didn'...
11
votes
0answers
104 views

Why does the Wolff algorithm slow down in a 4-body Ising model?

In the paper that introduced "Self-learning MC" (an ML-inspired MC technique, as I understand) the authors consider a many-body Ising model as an example to show the efficiency of their ...

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