Information technology and computing have undoubtedly been two of the surest bets in the history of human progress. When outstanding scientific questions can be translated to the realm of computing, they have a tendency of being answered (often very quickly), accelerating entire fields forward. With its continually improving performance and economy, modern high-performance computing is an indispensable complement to any modern scientific research program.
Quantum mechanical computations, only possible with the use of high-performance computing clusters, have proven to be very successful informing scientific models and delivering practical insights into the the function and performance of technologically important materials (Li-ion batteries to name one of many concrete examples). Specifically, "density functional theory" or DFT is a powerful formalism which was awarded the Nobel Prize for Chemistry in 1998 and has been a workhorse computational technique int he physical sciences (> 15,000 citations in 2015 alone*). Its ever increasing popularity is unsurprising as very accurate scientific insights can be made virtually while reducing the number of, or even eliminating altogether, expensive and resource-intensive physical experiments.
As computers inevitably improve or new computing paradigms emerge (such as quantum computing, as PM Trudeau has explained to us), the already powerful capabilities of computational materials science and quantum chemistry techniques will improve and keep extending further and further.
Overall, I recommend (1) high performance ocmputing to be considered as critical infrastructure (facilities/equipment) to Canadian fundamental science research and (2) computational materials science to be considered as an emerging platform technology with broad strategic interest and societal application.
Other than the arguments of proven scientific efficiency and economy of the method, these approaches to science also draw upon the existing strengths of a well-educated and computer technology literate Canadian population. Also, the current and future importance of high-performance computing is not lost on other nations, and to compare, the United States and China currently have 165 and 167 of the top 500 supercomputers in the world, respectively.**
*Jones, R. O. (2015). Density functional theory: Its origins, rise to prominence, and future. Reviews of modern physics, 87(3), 897.