Getting Started

To build

mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
make -j4

to run

export OMP_NUM_THREADS=8
./cppDFT ../default.inp

requirement

1. cmake 2.8.6 or above
2. c++11 compatible compiler
3. eigen3 include directory saved in EIGEN3_INCLUDE_DIR environment variable

Class Structure

Particle Management

• Particle
• ParticlePool
• ParticleSet

A particle is basically a collection of attributes such as posiotion, velocity, acceleration, mass and charge. A ParticlePool contains physical particles and is responsible for their memory allocation, deallocation and initialization. A ParticleSet maintains a list of pointers to the particles of interest.

The idea is to have a "heavy" object ParticlePool that manages memory allocation and then have mutiple "light" objects ParticleSet to manipulate the data. A typical starting point is

ParticlePool pPool(8); 
pPool.initCubicPositions(1.0);
ParticleSet gPset(pPool.myParticles());

which:

1. initialize 3 particles at the origin
2. call an initialization method to redistribute the particles - most simulations don't allow two particles at the same position
3. allow a particle set to control some particles in the pool (partial pool control is not yet implemented, so all particle sets are global particle sets at the moment)

Basis

• PlaneWave
• Gaussian

A basis function takes a position and returns a value

BasisSet

A basis set is simply a collection of basis functions with some methods to create, destroy and access these basis functions.

Function

• Density
• ExternalPotential
• HartreePotential

A function, like basis, also takes a position and returns a value. However, most functions need to be initialized as a linear combination of basis functions.