Amber masthead
Filler image AmberTools24 Amber24 Manuals Tutorials Force Fields Contacts History
Filler image

Useful links:

Amber Home
Download Amber
Amber Citations
GPU Support
Mailing Lists
For Educators
File Formats

How to obtain AmberTools24

AmberTools is a free, useful standalone package and a prerequisite for installing Amber itself. The AmberTools suite is free of charge, and its components are mostly released under the GNU General Public License (GPL). A few components are included that are in the public domain or which have other, open-source, licenses. The libsander and libpbsa libraries use the LGPL license.

The most recent version of the Amber 2024 Reference Manual in pdf format is always available on the web. It may help you to see if AmberTools meets your needs.

Option 1: Binary distribution via conda

Note: The conda package for AmberTools24 is not yet available. Instructions below are for AmberTools23. We will update this page when the new conda package is ready.

The conda package-management system can install a serial, binary (pre-compiled) distribution. This should work for Linux and MacOS systems, and may be sufficient for many users. It provides a simple way to get started with AmberTools, and to install it into many workflows. It does not provide access to parallel or GPU-enabled options, and the full source-code distributions are needed if you wish to combine AmberTools with Amber.

To install, proceed as follows:

  • If you don't have conda installed, please visit the Miniconda download page.

  • Those with an existing conda installation may wish to create a new conda "environment" to avoid conflicts with what you already have installed. To do this:

      conda create --name AmberTools23
      conda activate AmberTools23

    (Note that you would need to perform the "conda activate" step every time you wish use AmberTools23 in a new terminal; it might be appropriate to add this to your start-up script. Creating a new environment should not be necessary if you only use conda for AmberTools.)

  • Once this is done, type:

      conda install -c conda-forge ambertools=23

  • AmberTools is updated from time to time. To keep your conda package up-to-date, do this:

      conda update -c conda-forge ambertools

Thanks to Jaime Rodríguez-Guerra for spearheading this.

Option 2: Getting source code in tar format

This path is the traditional way AmberTools has been distributed. AmberTools is distributed in source code format, and must be compiled in order to be used. You will need C, C++ and Fortran90 compilers.

To download version 24 of the AmberTools distribution, please fill in the following form and click the "Download" button. The file size you should get is about 541 MB, and the md5sum is e4232d79e1eb69f679db75c2e6ac2906.

Note: Installation instructions are in Chapter 2 of the Amber 2024 Reference Manual. More detailed instructions for many systems may be found at the OS-specific requirements page.



How to obtain Amber24

Amber24 facilitates faster simulations (on parallel CPU or GPU hardware) and is distributed with a separate license and fee structure. Here is the license:

AMBER24 Software License

GRANT OF LICENSE. The Regents of the University of California grants, and you hereby accept, a permanent, non-exclusive license to use the Amber 24 software product ("Software") to the extent of its rights and in accordance with the terms of this Agreement. This licensed copy of the Software may only be used by you and members of your organization at your site who have read and agreed to this license. You may install the Software on computers at your site, or at other locations, provided that reasonable steps are taken to restrict use of the software to you and members of your organization. You may not distribute copies of the Software to others outside of your organization, and may make only those copies of the Software which are necessary to install and use it as permitted by this Agreement, or are for purposes of backup and archival records.

OWNERSHIP. This ownership is protected by the copyright laws of the United States and by international treaty provisions. Upon expiration or termination of this Agreement, you shall promptly terminate use of the Software and accompanying written materials.

MODIFICATIONS AND DERIVATIVE WORKS. You may modify the software, and use it to create derivative works, for your internal use at the site covered by this license. You may not distribute such modified or derivative software to others outside of your site without written permission. You may distribute the modifications themselves (e.g. as "patches") under terms of your choice. We encourage users to contribute modifications back into Amber, but you are under no obligation to do so.

ASSIGNMENT RESTRICTIONS. You shall not use the Software (or any part thereof) in connection with the provision of consultancy, modeling or other services, whether for value or otherwise, on behalf of any third party who does not hold a current valid Amber 24 Software License Agreement. You shall not rent, lease, or otherwise sublet the Software or any part thereof. You may transfer on a permanent basis the rights granted under this license provided you transfer this Agreement and all copies of the Software, including prior versions, and all accompanying written materials. The recipient must agree to the terms of this Agreement in full and register this transfer with the University of California.

LIMITED WARRANTY. LICENSEE acknowledges that LICENSORS make no warranty, expressed or implied, that the program will function without error, or in any particular hardware environment, or so as to generate any particular function or result, and further excluding any other warranty, as to the condition of the program, its merchantability, or its fitness for a particular purpose. LICENSORS shall not be liable for any direct, consequential, or other damages suffered by the LICENSEE or any others as a result of their use of the program, whether or not the same could have been foreseen by LICENSORS prior to granting this License. In no event shall LICENSORS liability for any breach of this agreement exceed the fee paid for the license.

UNIVERSITY OF CALIFORNIA'S LIABILITY. In no event shall the University of California be liable for any indirect, special, or consequential damages, such as, but not limited to, loss of anticipated profits or other economic loss in connection with or arising out of the use of the software by you or the services provided for in this Agreement, even if the University of California has been advised of the possibility of such damages. The University of California's entire liability and your exclusive remedy shall be, at the University of California's discretion, to return the Software and proof of purchase to the University of California for either (a) return of any license fee, or (b) correction or replacement of Software that does not meet the terms of this limited warranty.

NO OTHER WARRANTIES. The University of California disclaims other implied warranties, including, but not limited to, implied warranties of merchantability or fitness for any purpose, and implied warranties arising by usage of trade, course of dealing, or course of performance. Some states do not allow the limitation of the duration or liability of implied warranties, so the above restrictions might not apply to you.

Getting Amber24 for non-commerical use

Read the above license: note that it contains restrictions on usage and redistribution.

By filling out this form, you agree to the license, and confirm that all use will be non-commerical. Note that there is no license fee for non-commerical use.



The downloaded file will be about 173 MB, and have an md5sum of 0e9a01f2f2d5f0c1ebc75d2bdd5cde12.

Please note: You must also download and untar AmberTools24 using options 2, as described above. Installation instructions are in Chapter 2 of the Amber 2024 Reference Manual. More detailed instructions for many systems may be found at the OS-specific requirements page.

Getting Amber24 for commerical use

The license above is valid for both commerical and non-commerical usage. Only the license fee is different from commerical use. Commerical users should fill out this application for a commerical license. This will generate a license form that you can sign, and will contain information about how to pay the license fee.

Once payment is received, an email will be sent to the address you provide, containing a username and password, along with instructions on how to download the software.

Please note: The Amber24 license is a site license, valid for any number of users and any number of computers. The computers may be located anywhere (such as in the "cloud", or at remote computing centers.) Basically, the license deals with the affiliation of the users, and not with the location of the computing equipment itself.

Also note: Each release of Amber (which happens every two years) is treated as separate product, and requires a new license form and a new fee.


  • Academic/non-profit/government: $0. Use the "non-commerical" form, above.
  • Industrial (for-profit): $25,000 for new licensees, $20,000 for licensees of earlier versions of Amber.
  • Computing centers (operating on a not-for-profit basis) can license AMBER for a fee of $2000 and make executable code available to their users from non-profit organizations (no matter where such users are located, and irrespective of whether such users have their own Amber license). However, for-profit organizations who want to use the program at such centers must have obtained a separate license agreement with UCSF.
  • Hardware manufacturers and compiler vendors who want to use the program for porting, benchmarking and demonstrations ONLY may pay $500.
  • For multi-site or multinational for-profit companies, there should be a license fee paid per site.  See the on-line order form for more information.
  • Users who licensed Amber22 after January 1, 2024 are eligible for a free upgrade to Amber24. (This is not automatic: if you wish to obtain the new version, you need fill out and submit a new License Agreement, indicating that you are eligible for the upgrade.)

"How's that for maxed out?"

Last modified: May 3, 2024