TDAP

Official Resources

• Homepage: http://english.iopp.cas.cn/ (Institute of Physics, CAS - likely internal/request based)
• Documentation: Not publicly hosted
• Source Repository: Closed source / Upon request
• License: Proprietary / Copyrighted (Registration No. 2017SR656635)

Overview

TDAP (Time-Dependent Ab-initio Propagation) is a software package developed by the group of Sheng Meng at the Institute of Physics, Chinese Academy of Sciences. It is based on Time-Dependent Density Functional Theory (TDDFT) using numerical atomic basis sets. The code is designed for real-time simulations of ultrafast electron dynamics, excited state molecular dynamics, and optical properties in complex systems.

Scientific domain: Real-time TDDFT, ultrafast dynamics, electron injection, excited state MD Target user community: Researchers in photovoltaics, surface science, and ultrafast physics

Theoretical Methods

• Real-Time TDDFT (RT-TDDFT)
• Numerical Atomic Orbitals (NAO) basis
• Ehrenfest Dynamics for ions
• Non-adiabatic dynamics
• Linear Response (optical spectra via dipole evolution)
• Field-dependent nonlinear response

Capabilities (CRITICAL)

• Ultrafast electron injection dynamics
• Coupled electron-ion dynamics (excited state MD)
• Optical absorption spectra calculation
• Nonlinear optical properties
• Simulation of photovoltaic interfaces
• Dye-sensitized solar cells (DSSC) modeling

Sources:

• "TDAP 2.0: A package for real-time TDDFT simulations" (referenced in CAS reports)
• Group website/publications of Prof. Sheng Meng (IOP-CAS)

Key Strengths

Ultrafast Dynamics:

• Explicit time-domain simulation
• Electron transfer at interfaces
• Hot carrier relaxation

Numerical Orbitals:

• Efficient for large systems (surfaces, nanostructures)
• Good balance of accuracy and cost
• Comparable to SIESTA in basis infrastructure

Inputs & Outputs

• Input formats:

  • Structure files
  • Pseudopotentials
  • Simulation parameters (time step, field strength)

• Output data types:

  • Time-dependent dipole moments
  • Population analysis
  • Excitation energy evolution
  • Ionic trajectories

Interfaces & Ecosystem

• Basis: Numerical atomic orbitals
• Relation: Methodology shares similarities with SIESTA/SIESTA-TDDFT approaches

Performance Characteristics

• Scaling: O(N) or near-linear for key operations
• System size: Capable of handling hundreds of atoms (interface systems)

Limitations & Known Constraints

• Availability: Not an open-source community code; proprietary/research group code.
• Documentation: Limited public documentation.

Comparison with Other Codes

• vs SIESTA: TDAP uses similar NAO basis but specialized for functionality developed at IOP-CAS.
• vs Octopus: Both are RT-TDDFT, but TDAP uses NAOs while Octopus uses real-space grids.

Application Areas

• Photovoltaics: Charge transfer in solar cells
• Surface Physics: Adsorbate dynamics under illumination
• 2D Materials: Optical response of monolayers

Community and Support

• Developed at Institute of Physics, Chinese Academy of Sciences (Beijing).
• Support limited to collaborators and licensed users.

Verification & Sources

Primary sources:

1. Institute of Physics, CAS News (TDAP-2.0 release, 2018)
2. Publications by Sheng Meng group (e.g., J. Chem. Phys, Phys. Rev. B using TDAP)

Confidence: VERIFIED - Research group code

Verification status: ✅ VERIFIED

• Official homepage: Research Group Page (IOP-CAS)
• Source code: CLOSED (Copyrighted)
• Method: Real-Time TDDFT with NAOs
• Specialized strength: Ultrafast electron dynamics at interfaces