Powder Diffraction SIG 






Chair 2018

Daniel Shoemaker

Dept. of Materials Science & Engineering

Univ. of Illinois at Urbana-Champaign

260 Materials Research Lab

[email protected]






Chair-elect 2018/Chair 2019

Stuart Calder

Oak Ridge National Laboratory

1 Bethel Valley Road Bldg 7962, Rm 214

Oak Ridge, TN 37831

[email protected]





Past Chair

Olaf Borkiewicz

X-ray Science Div.

Argonne National Lab

9700 S. Cass Ave.

Argonne, IL 60439

[email protected]



Annual Reports


Annual reports contain information on the activities of the SIG for the year, issues addressed by the SIG members, future activity planning and any changes to the operations or constitution of the SIG.


2017 Report Download

2016 Report Download

2015 Report Download

2014 Report Download

2013 Report Download

2012 Report Download

2011 Report Download

2010 Report Download

2009 Report Download

2008 Report Download

2006 Report Download

2005 Report Download








I. Name


The name of this organization shall be the Scientific Interest Group on Structure Determination from Powder Data of the American Crystallographic Association.


II. Purpose


The purpose of this Group of the American Crystallographic Association (hereafter ACA) is to further the advancement of all aspects of powder diffraction aimed towards structure solutions and refinement based upon X-ray and neutron powder data and to promote communication between persons interested in such techniques and results.


III. Relationship to the American Crystallographic Association


The constitution of this group shall be consistent with the Constitution, By-laws, and Operating Rules of the ACA. In the event of conflict the Constitution, By-law and Rules of the ACA shall prevail.


IV. Membership


Membership in this group is open to all members of the ACA on application to the Secretary-Treasurer of this Scientific Interest Group and payment of the prescribed dues, if any.


V. Organization


The activities of this Group shall be administered by an Executive Committee of three officers elected by members of the Group. The officers of the Executive Committee shall be Chairperson, Chairperson-Elect and Past-Chairperson. It shall be the duty of the Chairperson to arrange, in cooperation with the ACA Program Chairperson, the Scientific Interest Sessions on Structure Determination from Powder Data for ACA meetings. The Chairperson-Elect shall serve in a special advisory capacity to the Chairperson and shall act in his capacity if for any reason the Chairperson cannot act. The Chairperson-Elect shall also serve to represent the Group to the Council of the Association and to be the Group's representative on the Program Committee of ACA meetings. Whenever possible, all notices to the Group shall be circulated along with the Newsletter of the ACA.


The term of office for each officer shall begin on the calendar year immediately following election. The Chairperson-Elect automatically succeeds to the Chairpersonship after one year. The Chairperson succeeds to Past-Chairperson after one year. Thus, a Chairperson-Elect is elected each year. Vacant, unexpired terms are filled by appointment by the Executive Committee.


The Executive Committee shall appoint a Nominating committee of three members, none of whom may be on the Executive Committee, to nominate candidates for election. The Nominating Committee shall be appointed by March 31st of each year and shall report its nominate to the Executive Committee by July 31st following. Other candidates may be nominated from the membership by petitions signed by five or more members. No persons may be regularly elected to any office of the Executive committee for more than two consecutive terms. Elections shall take place at the same time as do ACA elections.


VI. Activities


The Executive Committee and Group may engage in any activities consistent with the ACA Constitution, By-law, and Operating Rules, which in its opinion further the purposes of the Group. These activities include, but not restricted to, organizing a Structure Determination from Powder Data half-day session, in cooperation with ACA Program Chairman, at least once every two years at an ACA meetings.


VII. Elections and Voting


All votes shall be by mail ballot. Votes shall be by simple majority of those voting, except for votes on amendments to the Constitution (see IX.).


VIII. Dues


The Executive Committee may set dues to be charged to members of the group subject to an affirmative vote of the membership and to approval by the ACA Council. Such dues shall be collected and disbursed by the ACA Treasurer.


IX. Amendments


An amendment to the constitution may be proposed at any time by a petition signed by 5 % membership or 7 members, whichever is smaller, or by the Executive Committee. Amendments must be ratified by 2/3 majority of the members voting. Votes shall be by mail ballot.