Choose where your work begins.

First calculation with vibe-qc

1. 1 Install

   Clone the public source, then enter it and install:

   git clone https://github.com/vibe-qc/vibe-qc.git

   cd vibe-qc
   ./scripts/install.sh --dev
   source .venv/bin/activate

   install.sh builds the native core, creates a virtualenv and installs vibe-qc. It accepts --dev (track main) and --branch NAME; see the installation guide for the full surface and the manual native-deps recipe.

   GitHub HTTPS clones are anonymous. The installer above selects main from that origin; choose a published tag to pin a version. Source details.

2. 2 Run RHF on water

   Coordinates below are in bohr. With the environment activated, save this code as water.py in a working directory outside the source checkout. From that directory, run python water.py.

   import vibeqc as vq
   import numpy as np
   
   mol = vq.Molecule([
       vq.Atom(8, [ 0.0,  0.00,  0.00]),
       vq.Atom(1, [ 0.0,  1.43, -0.98]),
       vq.Atom(1, [ 0.0, -1.43, -0.98]),
   ])
   basis = vq.BasisSet(mol, "6-31g*")
   result = vq.run_rhf(mol, basis)
   
   eps = np.asarray(result.mo_energies)
   homo = mol.n_electrons() // 2 - 1
   print(f"E(SCF)  = {result.energy:.6f} Ha")
   print(f"ε(HOMO) = {eps[homo]*27.211386:.2f} eV")
   print(f"gap     = {(eps[homo+1] - eps[homo])*27.211386:.2f} eV")

3. 3 Read the result

   You get the SCF energy in hartree and the HOMO energy plus HOMO-LUMO gap in eV. Swap run_rhf for run_rks to run DFT, or call run_job(mol, basis="6-31g*", method="mp2") to add correlation: same front end, same objects. The methods page lists every route with its production, preview, experimental or gated label.