Grad School Year 2: The DFT Strikes Back

At some point, I'll write up a little something about the whirlwind tour of Spain that Justin and I enjoyed, but for now, the quarter starts today! It's weird being a second year. Over the next 10 weeks, I will have only one class to worry about, no teaching to distract me, and a whole lot of research to keep me busy.

It's exciting, frankly. I enjoyed my classes last year for sure but, thanks to LANL, I know what it feels like to just do science without other stuff gumming up my time. And I want that back. Being gone for two weeks was cool and all, but mostly I just want to return to "routine" (if there is such a thing in grad school) and dive into DFT.

The class starts today and I look forward to seeing how the class will enhance my understanding of the research I've done and the research I will do. Speaking of which, I should probably finish up the homework that's due in an hour.

Hola, ¿qué tal?

Hooray, Spain! After enduring my first trans-atlantic flight and a french-filled connection in Brussels (a place I will definitely visit in the future), I found myself in a rather alien place full of non-perpendicular roads and buildings that looked older than anything I'd ever seen before. San Sebastian is a very popular holiday location for europeans and I can absolutely understand why. The views are utterly breathtaking and the food is to die for. Since I don't speak spanish, I often just smile confusedly at the waiter or waitress who has been tasked with serving me until they suggest something, to which I always reply, "si, si. Gracias!"

Other than the sheer deliciousness, eating in Spain is a wholly different process because socializing outdoors is way more prevalent here than it is in the states. Lunch is a communal affair, lasting a few hours and a number of courses. Meals always feature alcohol (sometimes whether you order it or not) and coffee or espresso. The waitstaff never comes to ask you how you're doing because you're always busy chatting and, I must say, I'm completely taken with the way they do things here.

I lament that I can't speak the lingo because I feel like I'm missing out on the immersive nature of spending a week+ in a completely foreign place. Luckily, the conference is in english so I'll know just how little DFT I know.

Speaking of the conference, I'm currently at it. I'm sitting in an empty lecture hall trying desperately to digest the delicious food I ate for lunch while running some calculations. It's all fantastic. I like it here.

Whoa

I totally forgot to write last week because I was back in Irvine.

I've returned to UCI and I gotta say, it's nice to be back. As much as I was loving the extracurriculars out in New Mexico, I missed the sort of science we do here. We ask deep, theoretical, fundamental questions about DFT and that was not the sort of thinking/problem solving I was doing out at LANL.

I'm already working on something with Kieron and Aurora, which is really cool. It's nice to be on a project that feels as though it's wandering in uncharted territory. I'm also really engaged with the project because it's a finite-temperature kinda thing; that's the stuff I'm gonna be up to my eyeballs in really soon.

And the finite-temperature stuff looks so cool! The math is really pretty. There's all this groovy stat mech language lying underneath everything and I'm looking forward to seeing how everything ties together.

I'm also finishing up my first-year exam, as well as making a poster for Spain. Both of which are next week.

Hoooooly moly I'm going to be in Europe in like, 11 days.

Week 10: So long, farewell, auf wiedersehen, goodbye!

So that's it then. Dan and I finished our final project, uploaded it to the git repository (which crashed like, 16 times before everything was said and done), and had our final meeting with Charlie and Marc. They were both super cool and thanked us for our work this summer. Charlie also mentioned that either of us were welcome to come back next summer, which was nice to hear.

Saying goodbye was hard. I won't miss New Mexico all that much; I'm looking forward to moving back somewhere a bit more dense. I won't miss Los Alamos much either; it's beautiful for sure, but other than hiking and camping, there is absolutely nothing to do in that town. I will however miss the people. 

Over the course of these 10 weeks, the science has been fun and the green chile has been delicious, but above all else, I will remember the crazy camping hijinks, the late nights spent just talking about the inevitable existential questions one encounters while in grad school, the road trips all across New Mexico, the rock climbing followed by intense renditions of Don't Stop Believin' at karaoke night, and the 22 people I shared that dingy basement with.

It's been real, Computational Physics Workshop.

Week 9: Warning - This Post is Actually About the Program I'm In

On Wednesday, I woke up at 5:30 in the morning. I didn't need to, but my body pulls this stunt every time I know I have a presentation to do. It's a mixture of anxiety caused by the fear of oversleeping and anticipation because my god, do I love giving presentations.

I managed to fall back asleep for a half hour or so until waking up again, this time just 30 seconds before my alarm was going to go off anyway. I rolled out of bed, spruced up the beard, brushed my teeth, showered, picked out a shirt and tie, threw on those socks my dad got me for christmas that are covered in mathy equations, fed my landlady's cat, and began walking to the bus stop.

The bus seemed to travel far slower than usual this morning. The greens and browns of the northern New Mexican high desert smeared past the Park 'n Ride shuttle window while Green Day (Nimrod, in case you're curious; it's a solid album) wafted out of my earbuds. Once we arrived in Los Alamos, I wandered past security up to Research Park. I found the conference room that would be my home for the rest of the day, located the free coffee, and engaged in the nervous but pleasant chatter that always proceeds a "big" speaking engagement.

The day was split into two parts. First, we'd each give a quick, 3 minute presentations that would outline the longer talks we would give later in the day. The higher-ups at LANL would attend these quick-looks and use them to decide which talks they'd like to see in the afternoon. It was made very clear early on that between the short and long talks, the short ones were the important ones. Our coordinator also made sure to explain that the 3 minute time limit was a hard one. We had a schedule, and we were going to stick to it.

After finishing my cup of coffee, I found my partner and complimented his outfit. The dude wore a full on suit and looked sharp as hell. I felt silly but was glad I'd decided to at least wear a tie. As 9 o'clock drew nearer, we were told to grab seats towards the back so that the important people could sit in the front. The clock struck precisely 9:04 and we began. The first few talks flew by pretty quickly and I could feel adrenaline slowly leeching into my bloodstream as group after group inundated the room with their concentrated morsels of science. The first warm dense matter (WDM) group (who ran orbital free stuff) went up and dropped a few of our punchlines but before I knew it, Dan was up.

His presentation went really well. In it, he detailed what WDM is, why it's tricky to model, why we care about it, and how to calculate electrical resistivity using the Ziman-Evans formula. Before I could blink, he was done, the audience was applauding, and my presentation was already up on the wall.

We were mandated to provide an introductory slide before getting into the science so naturally, I dotted it a few jokes, a Star Wars quote (both of which went over well), and self-depricated about being from New Jersey. Then I got down to business. Our most exciting data was on display for the whole room to see. I felt like I did a solid job of explaining what our conclusions were, why they were significant, and why it was worth coming to our longer talk later in the day. We had a story and it felt pretty compelling. It was over before I knew it, but apparently Dan and I made a convincing argument for coming to see our talk.

When the afternoon session rolled around, there were far fewer people in the room. Friends had come by for the earlier talks (probably because they were short and came with the prospect of free coffee) but now, only summer students, mentors, and a few lost lab employees were present. That is until the WDM presentation(s) started. The room noticeably swelled up and I saw some faces I recognized. Obviously, Charlie and Marc were there since they were our mentors, but there were some other DFT-ers in the room, too. The long talk was an utter joy to give. Dan and I were really able to get down to the meat of how our calculations worked. I got to explain how we eliminated a handful of models, how we selected our exchange-correlation functional, and what our future goals with this code might be. We even got some questions, and I was even able to answer them. It was pretty groovy.

Then our presentation was over. And all the WDM people left. And the room was far less full. It was cool. Our science felt important. The rest of the afternoon was... long. The presentations were good, but four hours of constant exposure to 20 minute snipits of science is exhausting. By the end of it though, we were all relieved to be over this penultimate hurdle (I still have to write this paper-thingy). We all felt accomplished. It was a clear demarcation in the program.

The program is almost over.

Week 8: 748 Miles

Sorry for the late post, but this was one heck of a busy weekend.

First, I suppose I should mention something work related. The bug hasn't been fixed, my plot is still kinky, but our results are solid everywhere else and the project is drawing to a close. This week we will be giving our final presentations and I can't wait to do so. I've always enjoyed giving talks and I've been sitting with this data for so long that it will be nice to talk about it with some strangers. It also sounds like we might get a paper out of this summer which is nice.

On to the fun though. On Friday, myself and four other students piled into the back of a Subaru Outback and began traveling towards southern New Mexico. The first destination on our list was White Sands National Monument. If you're ever in New Mexico, you need to make it a point to get down there. The park is completely covered in white gypsum sand and is so large that you can very clearly see it on google maps. We spent the better part of an evening there and camped nearby overnight. Seeing the moonrise over that place was seriously spine tingling.

Then things got even better. We broke down camp and traveled over to Carlsbad Caverns, the largest cave in the US (contiguous maybe? I don't remember). The cave itself is broken down into a few rooms that have paths laid out for you to walk on. Pictures don't do it justice (and also I haven't ripped them off my phone yet). The cave was originally a sea and most of the features down there are either fossilized coral or stalagmites which have formed from drips and drops over the course of millions of years. If you head there and have somewhere nearby to stay at for the night, you can watch the bats fly out around 7 pm. We however needed to find another place to camp, so we left after doing the hike.

We ended up camping at Bottomless Lakes State Park, a place I'd happily camp at again. The views were lovely and we got to watch a series of thunder storms (that were safely far away from us) light up the sky. The clouds recessed and left us with an incredibly clear sky full of stars and another beautiful moon.

Moral of the story: if you like to be outside, you need to head to New Mexico at least once. Possibly twice.

I know I'll certainly be back before too long. Oh also, 748 miles is how far we drove. Over the course of three days. I'm just now starting to get feeling back in my legs.

Week 7: Kinks

That title is totally click-bait. But I swear it's relevant!

I finally hit a massive obstacle in my project earlier this week. One of the plots I generated had a pretty nasty kink in it where it shouldn't have had one. This lead to a number of days spent under the hood of my code debugging, re-writing subroutines, checking types, and making sure I didn't exceed the 132 character/line limit (thanks for nothing, Fortran 90).

Today, I finally had a break through. The plot I was generating featured points whose y-values came from an integrand. The integrand is chock full of... interesting quantities that are computational expensive to calculate. The two most complex are the external potential and the structure factor, both of which come from a program that, for all intents and purposes, is a black box to me.

None of my other plots had any issues, so from the outset I was suspicious that the issue was in my code. Still, I started from the top of my integration routine and worked all the way down until it had to be something in my integrand itself that was misbehaving. I checked the fermi-dirac function I was using, the physical parameters that gave the integral correct units, the fineness of my grid, and even how many digits of pi my code was using. Finally I came to the potential and the structure factor. It had to be one or the other. Removing each separately showed that there was an unusual jump in the potential where my kink was. Victory.

The win is hollow though. I still have no idea why the potential is misbehaving and although it looks like that's the issue, I can't really be sure. I just hope that whatever the issue is, it won't have affected the rest of our results.

I can't believe that it's already the end of week 7. Before I know it, I'll be back at sea level and won't need a cryptocard to check my email.