Get RCR and citation metrics for a list of pubmed IDs from https://icite.od.nih.gov/analysis

getPubMetrics.R

#' Get publication metrics from iCite
#' 
#' iCite is a tool to access a dashboard of bibliometrics for papers 
#' associated with a portfolio. Users upload the PubMed IDs of articles 
#' of interest (from SPIRES or PubMed), optionally grouping them for 
#' comparison. iCite then displays the number of articles, articles per 
#' year, citations per year, and Relative Citation Ratio (a field-normalized 
#' metric that shows the citation impact of one or more articles relative 
#' to the average NIH-funded paper). A range of years can be selected, 
#' as well as article type (all, or only research articles), and individual 
#' articles can be toggled on and off. Users can download a report table 
#' with the article-level detail for later use or further visualization. 
#' 
#' @param pmids a vector of numeric pubmed IDs
#' 
#' @return a data frame with citation information
#' 
#' @depends httr
#' @export
getPubMetrics = function(pmids) {
  require(httr)
  do.call(rbind,lapply(pmids,function(pmid) {
    return(content(GET(sprintf('https://icite.od.nih.gov/api/pubs/%d',pmid))))
  }))
}

got what I needed-
https://icite.od.nih.gov/api/pubs?pmids=25539595,25460919,25456083,25285016&format=json

Thanks, @morgenweck. I need to adjust the code a bit to do a better job of doing multiple lookups.