J. Plasma Fusion Res. SERIES, Vol.7 (2006) 338-342

Development of the Atomic and Molecular Data Markup Language
for Internet Data Exchange
RALCHENKO Yuri, CLARK Robert E.H.1 , HUMBERT Denis1 ,SCHULTZ David R.2 , KATO Takako3 and RHEE Yong Joo4
National Institute of Standards and Technology, 100 Bureau Dr, Gaithersburg, MD 20899-8422, USA
1 IAEA, P.O. Box 100, Wagramerstrasse 5, A-1400 Vienna, Austria
2 Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6372, USA
3 National Institute for Fusion Science, Toki 509-5292, Japan
4 KAERI, 150 Duck-Jin-Dong, Yusong-Ku, Taejon 305-353, Korea（Received: 5 October 2004 / Accepted: 10 January 2006）

Abstract
Accelerated development of the Internet technologies, including those relevant to the atomic and molecularphysics, poses new requirements for the proper communication between computers, users and applications.
To this end, a new standard for atomic and molecular data exchange that would reflect the recent achievementsin this field becomes a necessity. We report here on development of the Atomic and Molecular Data Markup
Language (AMDML) that is based on eXtensible Markup Language (XML). The present version of theAMDML Schema covers atomic spectroscopic data as well as the electron-impact collisions.
Keywords:
atomic and molecular data, Internet, data exchange, XML
1．Introduction
The amount and complexity of atomic and molecular data exchanged over the Internet necessitate development of new standards and verification tools that
could guide the users in these activities. The previous standard for atomic and molecular data exchange,
ALADDIN (from A Labeled Atomic Data Interface),
was developed in order to provide a standard and flexible format and interface for the exchange and management of atomic, molecular, and plasma-surface interaction and material properties data of interest tofusion research [1]. It was originally designed byR. Hulse at the Princeton Plasma Physics Laboratory and then adopted by the International Atomic Energy Agency (IAEA) and the Atomic and Molecular Data and Plasma-Material Interaction (A + M/PMI)
Data Centre Network (DCN) for the exchange of data
since 1988. ALADDIN consists of a set of Fortran-77
programs that provides for interactive data search, terminal display, and data manipulation capabilities. ALADDIN was designed on very general principles, which
made it applicable to a wide variety of databases andtheir interfacing to a similar variety to data application
codes.
Development of ALADDIN was an important stepin providing users with modern strategies and tools

for data exchange, and its significance has quickly become obvious for researchers working in fusion applications, plasma physics and diagnostics, and other disciplines. Nonetheless, an extremely fast advance ofcomputer technologies, as well as the Internet in general and World Wide Web (WWW) in particular, callsfor exploration and development of new approaches andtechniques in atomic and molecular (A + M) data exchange, which would reflect the recent achievements inthe aforementioned fields. The present paper describes
our approach to development of the new A+M data exchange standards.
2．XML and A + M data exchange
The eXtensible Markup Language (XML) [2] wasoriginally designed to meet the challenges of large-scale
electronic publishing. Nowadays XML is also playing
an increasingly important role in the exchange of a wide
variety of structured data on the Web and elsewhere and,in fact, has become a cross-platform, extensible, andtext-based standard for representing data. As a metalanguage, XML is used to develop new, more specific,
markup languages for very diﬀerent applications andrealms of human activities such as, e.g., government,C 2006 by The Japan Society of Plasma

Science and Nuclear Fusion Research
Corresponding author’s e-mail: yuri.ralchenko@nist.gov

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Development of the Atomic and Molecular Data Markup Language for Internet Data Exchange

bibliography, physics, finances, etc. In addition to general rules on how to create documents within a specificmarkup language, there are validation tools that checkconformance of documents to the relevant standards.
Among various XML methods and techniques, theXML Schema language (see, e.g., [3]) is one of the mostpowerful and flexible ones. A schema can be used tovalidate such important features as the structure and order of the markup elements and attributes, and order ofthe markup elements and attributes, the data values ofattributes and elements based on types, ranges, enumerations and pattern matching, and the uniqueness of values in an instance, to name a few. Besides, schemas canprovide default and fixed values for the data elements
and attributes as well as documentation about the data
in an XML document. These and other important features make the XML Schema very appropriate for ourpurposes.
There have recently been some attempts to develop either very general specifications for scientificdata, e.g., eXtensible Data Format [4], or very specificschemas, e.g., SpectroML for molecular spectrometry
data [5], neither of which can adequately serve the purpose of the A + M data exchange. Therefore, in October
2003, the IAEA DCN decided to form a working groupon development of the XML-Schema-based Atomic andMolecular Data Markup Language (AMDML) that issupposed to replace ALADDIN as the standard for theA + M data exchange.

original data. For the former, the fitting function expression and fitting parameters are provided as well. In allcases, the numerical data may be supplemented by accuracy estimates and relevant bibliographic references
and/or comments. An example of an AMDML-valid
data file for radiative and collisional transitions between
the 2s2 1 S and 2s2p 1 Po terms in C III is presented in theAppendix. The draft version of the AMDML Schema
will be shortly distributed on the DCN web sites for usercomments and suggestions.
AMDML will oﬀer a number of advantages over ALADDIN. One of the most important is the possibility of
automatic data validation which can be exemplified byseveral entries in the C III file in Appendix. For instance, the spectroscopic charge of an ion given by thespectrCharge parameter is allowed to take only positive integer values, while the parity parameter can
only take values “−1” or “1”. For the complex datatype orbitalMomentum, its character component must
only be a letter while the numerical component givenby the l Value parameter must be a non-negative integer. The AMDML data validation approach adds solid
physical considerations to the contents of the data file
thereby correcting possible errors and misprints. Also,
the AMDML data files may include an explicit expression for the fitting function with a detailed identificationof the fitting parameters. This would allow a direct generation of fitted data by applications.
4．Conclusions
The importance of the A + M data exchange via theInternet is widely recognized. We presented here thefirst attempt to develop a new standard which is basedon the most advanced Internet technologies for structured data exchange.

3．AMDML schema
The present development version of ADMDL
Schema covers atomic spectroscopic data and electronimpact collisions with atoms and ions while theheavy-particle collisions will be dealt with in the nextversions. An XML data file must have a mandatory
block describing the atomic states and several optional
blocks describing various radiative and collisional
types of transitions between those states. The schema
allows diﬀerent levels of generalization for presentationof the atomic states, e.g., levels, terms, configurations,etc., which are complemented by detailed information on state properties including energies andvarious quantum numbers. The radiative block provides data on transition probabilities, transition type,etc. The collisional blocks may contain both original experimental and/or theoretical data and fits of the

[1]

[2]
[3]
[4]
[5]

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References
R.A. Hulse, in: Atomic Processes in Plasmas, ed.
by Y.-K. Kim and R.C. Elton, Gaithersburg, MD
1989 (AIP 1990), p.63.
URL http://www.w3.org/XML/.
P. Walmsley, Definitive XML Schema (PrenticeHall PTR, Upper Saddle River, NJ, 2002).
URL http://xml.gsfc.nasa.gov/XDF.
M. A. Rühl et al, Journal of the Association forLaboratory Automation, 6, 76 (2001).

Development of the Atomic and Molecular Data Markup Language for Internet Data Exchange

APPENDIX<?xml version="1.0" encoding="UTF-8"?><!--Sample XML file generated by XMLSPY v2004 rel. 4 U (http://www.xmlspy.com)--><atomicTransition xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="C:\temp\adml1.xsd"><atomicStates><atomicState><element nuclearCharge="6">C</element><spectrCharge>3</spectrCharge><stateID>ID1</stateID><ionCharge>2</ionCharge><parity>1</parity><energy units="eV"><value>0</value></energy><ionEnergy units="eV"><value>47.864</value></ionEnergy><state stateType="term"><component><configuration><core><elementCore nuclearCharge="2">He</elementCore><term><LS><L><l>S</l><l_Value>0</l_Value></L><S>0</S></LS></term></core><shells><shell><principalQN>2</principalQN><orbitalMomentum><l>s</l><l_Value>0</l_Value></orbitalMomentum><numbElectrons>2</numbElectrons><parity>1</parity><shellTerm><LS><L><l>S</l><l_Value>0</l_Value></L><S>0</S></LS></shellTerm></shell></shells></configuration><term>
<LS>
<L>

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Development of the Atomic and Molecular Data Markup Language for Internet Data Exchange<l>S</l><l_Value>0</l_Value></L><S>0</S></LS></term></component></state><statWeight>1</statWeight></atomicState><atomicState><element nuclearCharge="6">C</element><spectrCharge>3</spectrCharge><stateID>ID2</stateID><ionCharge>2</ionCharge><parity>-1</parity><energy units="eV"><value>12.690</value></energy><state stateType="term"><component><configuration><core><elementCore nuclearCharge="2">He</elementCore><term><LS><L><l>S</l><l_Value>0</l_Value></L><S>0</S></LS></term></core><shells><shell><principalQN>2</principalQN><orbitalMomentum><l>s</l><l_Value>0</l_Value></orbitalMomentum><numbElectrons>1</numbElectrons><parity>1</parity><shellTerm><LS><L><l>s</l><l_Value>0</l_Value></L><S>0.5</S></LS></shellTerm></shell><shell><principalQN>2</principalQN><orbitalMomentum><l>p</l><l_Value>1</l_Value></orbitalMomentum>

341<numbElectrons>1</numbElectrons><parity>-1</parity><shellTerm><LS><L><l>p</l><l_Value>1</l_Value></L><S>0.5</S></LS></shellTerm></shell></shells></configuration><term><LS><L><l>p</l><l_Value>1</l_Value></L><S>0</S></LS></term></component></state><statWeight>3</statWeight></atomicState></atomicStates><radData><transition><initialStateID>ID2</initialStateID><finalStateID>ID1</finalStateID><transitionProbability><oscStrength><value>0.7586</value></oscStrength></transitionProbability><wavelength lineSource="Ritz" units="Angstrom"><value>977.020</value></wavelength></transition></radData><collData><transition><process>collExcitation</process><projectile><electron/></projectile><initialStateID>ID1</initialStateID><finalStateID>ID2</finalStateID><energyUnits>eV</energyUnits><threshold units="eV"><value>12.690</value></threshold><dataType>CrossSection</dataType><collDataUnits>cmˆ2</collDataUnits><data><fitData><fitValidityLimits>

Development of the Atomic and Molecular Data Markup Language for Internet Data Exchange<lowerLimit units="eV"><value>12.690</value></lowerLimit></fitValidityLimits><fittingFunction><name>Function1</name><expression>y = A/X + B/Xˆ2 + C/Xˆ3 + D/Xˆ4+E*ln(X)/X</expression><indepVariable>y</indepVariable><depVariable comment="energy in threshold units">X</depVariable><parameters><parameter name="A"><paramValue>-1.974e-16</paramValue></parameter><parameter name="B"><paramValue>8.347e-16</paramValue></parameter><parameter name="C"><paramValue>-3.640e-16</paramValue></parameter><parameter name="D"><paramValue>5.952e-17</paramValue></parameter><parameter name="E"><paramValue>4.539e-16</paramValue></parameter></parameters></fittingFunction><comments>This function provides correct asymptotics for optically allowed transitions.
Original Data were calculated with the Coulomb-Born-exchange method</comments></fitData></data></transition></collData></atomicTransition>

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