A description of the DEPOSIT computer code is presented. The code is intended to calculate total and m-fold electron-loss cross-sections (m is the number of ionized electrons) and the energy T(b) deposited to the projectile (positive or negative ion) during a collision with a neutral atom at low and intermediate collision energies as a function of the impact parameter b. The deposited energy is calculated as a 3D integral over the projectile coordinate space in the classical energy-deposition model. Examples of the calculated deposited energies, ionization probabilities and electron-loss cross-sections are given as well as the description of the input and output data. Program summaryProgram title: DEPOSITCatalogue identifier: AENP_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENP_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: GNU General Public License version 3No. of lines in distributed program, including test data, etc.: 8726No. of bytes in distributed program, including test data, etc.: 126650Distribution format: tar.gzProgramming language: C++.Computer: Any computer that can run C++ compiler.Operating system: Any operating system that can run C++.Has the code been vectorised or parallelized?: An MPI version is included in the distribution.Classification: 2.4, 2.6, 4.10, 4.11.Nature of problem: For a given impact parameter b to calculate the deposited energy T(b) as a 3D integral over a coordinate space, and ionization probabilities Pm(b). For a given energy to calculate the total and m-fold electron-loss cross-sections using T(b) values.Solution method: Direct calculation of the 3D integral T(b). The one-dimensional quadrature formula of the highest accuracy based upon the nodes of the Yacobi polynomials for the cosθ=x∈[−1,1] angular variable is applied. The Simpson rule for the φ∈[0,2π] angular variable is used. The Newton–Cotes pattern of the seventh order embedded into every segment of the logarithmic grid for the radial variable r∈[0,∞] is applied. Clamped cubic spline interpolation is done for the integrand of the T(b).The bisection method and further parabolic interpolation is applied for the solving of the nonlinear equation for the total cross-section. The Simpson rule for the m-fold cross-section calculation is applied.Running time: For a given energy, the total and m-fold cross-sections are calculated within about 15 min on an 8-core system. The running time is directly proportional to the number of cores.