Top 20 countries in chemistry based on citations per paper

	Country/Territory	Papers	Citations	Impact
1	United States	219,562	3,7,154	14.93
2	The Netherlands	18,483	3,438	14.79
3	Switzerland	17,603	253,035	14.37
4	Sweden	14,409	177,630	12.33
5	England	55,779	672,998	12.07
6	Canada	31,310	348,660	11.14
7	Germany	94,321	1,043,013	11.06
8	Belgium	12,433	128,220	10.31
9	France	64,302	658,095	10.23
10	Italy	40,124	404,565	10.08
11	Australia	17,215	173,087	10.05
12	Spain	42,567	402,612	9.46
13	Japan	115,434	1,083,153	9.38
14	South Korea	31,453	222,720	7.08
15	Taiwan	17,673	124,194	7.03
16	Czech Republic	10,088	70,617	7.00
17	Brazil	16,716	100,168	5.99
18	Poland	26,883	149,670	5.57
19	India	53,301	281,481	5.28
20	Turkey	11,079	52,814	4.77

The data above were extracted from the Essential Science Indicators database of Thomson Reuters. This database, currently covering the period January 1998 to April 2008, surveys only journal articles (original research reports and review articles) indexed by Thomson Reuters. Articles are assigned to a category based on the journals in which they were published and Thomson Reuters’s journal-to-category field definition scheme. Both articles tabulated and citation counts to those articles are for the period indicated. Here our ranking in chemistry is by citations per paper – among nations that published 10,000 or more papers – to reveal weighted impact. For articles with multiple authors from different nations, each nation receives full, not fractional, citation credit. Essential Science Indicators lists nations ranked in the top 50 per cent for a field over a given period, based on total citations. In chemistry (which as here defined excludes dedicated biochemistry journals), 92 nations are listed, meaning 184 were surveyed. Twenty-two nations published at least 10,000 papers during the period. Notable are those that produced relatively few papers but achieved a high citations-per-paper score, namely the Netherlands, Switzerland, Sweden and Belgium (all in the top ten). For more information on Thomson Reuters’s Essential Science Indicators, see http://scientific.thomson.com/products/esi. Also see: http://scientific.thomson.com