It was at the badging office of NASA Ames that I first met Tim when I came to present a talk. Tim had already arranged for me to be fingerprinted in the anticipation that my NASA Postdoctoral Program fellowship proposal, which I was still writing, would be accepted, and told me that I should hit the road running once I got here. He told me over lunch that he knew stability was a very important aspect of our lives and he was already thinking to extend my two-year NPP postdoc to the third year if I wanted that. I knew then that he was already thinking a few steps ahead, and it allowed me to concentrate on the science. We published our first paper together out of my postdoc work on the origin of high global warming potentials of some green-house gases within a few months. We have published many since then and more are yet to come. Tim’s expertise spanned from quantum chemistry to astrobiology and everything in between. Now, after fourteen years, I feel like our work together was abruptly cut short by his passing.

Over the years of working together we grew closer and became from a mentor and mentee to colleagues and friends. During our many work trips to Pleasanton, where we went once every couple of months to meet with Prof Head-Gordon, our conversations ranged from electronic structure theory, scientific computing, and astrobiology to parenting, baseball and cricket, and many more topics. I have learned more about parenting from Tim than anyone else. Tim has always shown an open mind during our many spirited discussions. I appreciated, among many other things, his openness to new ideas, his generosity, support, trust, and his encouragement for independence and initiative. I leaned heavily upon Tim’s mentoring, and I miss it every day.

Tim, you have significantly impacted my personal and professional lives in innumerable ways that I am unable to describe. Thank you.

Dear Julia and family, we were incredibly saddened by Tim’s passing. The community lost a great scientist. Our family sends you the most sincere condolences. 

With affection,

Vanda Glezakou and Stephen Elbert

Tim and I overlapped as graduate students in Berkeley. I met him at several conferences in the last 30 years. He was a considerate person and conscientious and committed scientist. I'm shocked and saddened to learn of his death.

Tucker Carrington

Dear Julia and family:

I was terribly saddened to hear of Tim’s sudden passing. I cannot imagine how difficult it is to process this loss.

I hunted hard for some pictures I might have been able to share, but sadly could not locate any. Instead, I will just leave these comments, because although we did not have a chance to work together directly, I felt like I knew Tim well. So, while I could confirm my deep respect for Tim’s quiet brilliance as a scientist – as have so many others here have done – I really want to emphasize my recollection of how good-natured, warm-hearted and generous Tim was; to everyone, including to me, as someone who had left the scientific fold. (I was always touched and honored that Tim and Julia still regarded me as a member of the quantum chemistry community after so many years.) Tim brought his characteristic positive and gentle attitudes effortlessly to everything I saw him do. And I also realized, as came to reflect on this sad news, that I could actually remember something specific that Tim had said at practically every occasion I had seen or met him. And this goes back more than 20 years. Not many people have such an easy and lasting impact on those around them.

Indeed: life is dreadfully hard and unfair when we lose the brightest and best at such a young age, when they still had so much more to give. Treasuring those memories becomes ever more vital, as we give thanks for so many positive times.

Richard

I was heartbroken when I heard the news of Timothy's passing.  He was not only brilliant in the work he left to this world but he was a beautiful human to all, especially those he loved. My heart is with you all at this difficult time and offer any help I can give.

Love and respect to all!

Roni

In memory of a brilliant chemical scientist who contributed much to society and the world 

A dear son in law who was a continual support to his devoted  wife and three sons. He. Will be greatly missed.   

With love  and fond memories   Doris  Rice.     

I must apologize for my delinquency in messaging here.  I, frankly, am devastated.  Tim was my hero in many ways.  Beyond maybe my parents, wife, and PhD advisor, no other single person more greatly influenced my life more than Tim.  I echo what everyone else has said.  He cared about others, especially his family (whom he talked about constantly) and those whom he mentored and for whom he served as branch chief.  Tim took care of everyone.  He especially took care of me.

Tim and I published nearly 50 papers together.  Our last one, sadly, will come out in just a few weeks' time.  Simply writing that leaves a hole in my heart making it no longer whole.  He was so encouraging of my scientific wandering and found ways to be excited about it, too.  He knew how to steer me to more useful things and took care not to overwork me or step on any of his other mentees' toes.  This continued well after my postdoc when he made sure I got paid in the summer.  This was huge to wife and me as we had just welcomed our first child into the world.  Tim took care of us all.  He did it not by trying; he did it just by being whom he was.

The last time I talked to him, we were still discussing research that needed to get done.  He had so many plans for what he wanted to accomplish.  He also wanted to make sure that his current postdoc was taken care of, as well, as always.  Tim was a fount of scientific experience and creativity.  He could make tedious tasks seem routine and knew how to leverage his experience and that of his group and collaborators toward novel scientific outcomes.  He didn't do this for awards or prizes.  He did it because he wanted to.  He wanted to know what the answer was.

Currently, I'm stuck on a project, and I need his help.  Only this time, he's not there to give it.  I know he would love to discuss this and pick it apart.  He'd give his wisdom and send me on to do the hard work.  Strangely, it wouldn't seem so hard after talking about it with him.  Now, that is no more.  I just hope and pray that I can build those same experiences and stand on his shoulders to push science forward because that's what he would have wanted most of all.

Godspeed, my friend.  You have '"slipped the surly bonds of earth" to "touch the face of God."' My prayers are with your family: your dear wife and your sons whom I feel like I know even though I've only met them on a couple of occasions (expect for that time Trevor's phone went snorkling in Hawaii).  My life is emptier with you gone.  Thank you for making it more full in the first place.

My deepest condolences to Tim's family. Tim was willing to support my NPP application in 2021 when the new pandemic rules prevented the submission. Tim's was willing to support my studies and provided me with meaningful insights on how  to merge the astronomical problem with the quantum chemistry problem. I am deeply sad for this terrible news and I wish all the best to his family.

Dario

It was Tim who offered me the opportunity to become a NPP postdoc at Ames in 2006.  It was Tim who gave me selfless, invaluable and sincere advice at sensitive moments.  It was Tim who always planned ahead and kept encouraging us to explore and pushing for new frontiers of research, with a lot of patience.

Without Tim, I wouldn't have come to the Bay Area to do what I have been doing,  and might have had a very different life elsewhere.  Without Tim, I probably would have lost or abandoned my scientific career a long time ago.  Without Tim, a lot of things would not have been as easy or smooth as they were ... His support and kind help have been a constant throughout my career.

It was such a privilege and honor to work for and with Tim. He was an incredible mentor and friend. He will be in our thoughts and prayers forever. May the memories help you find peace, strength and comfort.

I send my deepest, heartfelt condolences to Tim's family. 

I was shocked and am extremely saddened by Tim's passing. I joyfully worked very closely with him for more than 25 years and miss him dearly. 

Tim had a big heart for service, helping people under him, and trying to improve things. The devotion Tim had to his family was exemplary, and a lot of that attitude transferred over to the people with whom he worked.

We worked well together and tackled many different things ranging from starting the productive International Space Act Agreement with the Dutch, significantly expanding the Astrophysics and Astrochemistry Labs and capabilities at Ames, and creating a new research program centered on carbon. During the past few years, despite Covid shutdowns, Tim’s unique computational expertise helped pioneer a new way to interpret Webb telescope observations. All of us involved in that deeply miss Tim’s irreplaceable patient, gentle, and firm guidance.

During the earlier part of the years I’ve known him, come Spring, Tim left work dressed for serious time on a baseball field with his sons, coaching and refereeing. His game stats were as detailed then as his quantum notes today. In more recent years, Tim supported his children’s studies with NASA lab internships.

Remarkably, as far as any of us could tell, Tim’s dedication to family and research was not diminished as he took on the responsibilities and burdens of NASA management.

I will miss our conversations and Tim’s perspective on many things as will his collaborators, the Ames community, and the world-wide research community. 

Really sad to hear about Tim. He was a lovely man and I wish you all the best in these difficult times. 

with best wishes

Chris & Helen Murray

I have known Tim since my second or third year of graduate school. He always gave great advice about quantum chemistry problems that I was wading into as a novice scientist. Near the time I earned my PhD at University of Georgia in 2005, I hoped that he would have a postdoc opening available at NASA, but his funding situation didn't match my job search. 

I never got to know Tim as well as I wanted to and we never got to publish together. I am thankful that he did such an amazing job mentoring Ryan Fortenberry and Partha Bera, who have become two of the most generous and hard-working scientists I have known. I am thankful for Tim's laid back wisdom, available any time I needed it. 

At the Fall 2019 ACS Meeting, by happenstance several theoretical chemists had a late flight out of San Diego and we seemed to converge to the same restaurant looking for a snack and a few drinks before heading out. Tim and Julia were among the group, which was great because I had never really chatted with Julia before. In perfect CA weather, we all had a lot of laughs and good conversation. It was one of the first times in my career that I truly felt like an equal around some of the giants in the field. Even when Tim was still with us, it became a cherished pre-pandemic memory. 

My heart goes out to everyone who loved Tim and was inspired by his kindness and his intellect. 

I'm not really sure where to begin.  Tim and I have been friends and colleagues for a long time and our friendship and joint work just mingled into a single thing.   Our conversations often skipped back and forth between astrochemistry, what our kids were up to, the latest weird thing one of had heard about, and so on.  It was just plain fun when we got together.  And productive too.  Working together, we were able to do things that we never would have been able to do on our own.

Our conversations occasionally contained a certain amount of good-natured teasing.  Some of it was good old-fashioned pretend rivalry between a lab guy and a theory guy, but we could also fall back on the required  rivalry of our respective alma maters - the Colorado School of Mines for Tim, and the New Mexico Institute of Mining and Technology for me.  It is going to be a personal challenge to me to make a gift in his name to the Colorado School of Mines, as requested by his family, but I can hear him laughing gleefully about it in my mind right now and I know I will make the donation with a smile.

One of the more amusing things about working with Tim is that our conversations were sometimes made more complicated by simultaneously being each others bosses.  For example, when he was my Division Chief, he was a CoI on several grants on which I was the PI and there were times when he would have to ask me to do something for him on a grant that then required I ask him for a approval signature as my Division Chief.   Somehow we alway made it work, even if we weren't always sure who was in charge at any given moment.

I was devastated when I heard Tim had passed away and I am sure I am going to be processing this for a long time to come.  I was lucky to have had him my life and I'll always be grateful for that.  Gonna miss you so much, Tim.

Finally, my condolences to Tim's family.  He spoke of you often and always in a manner that showed how very special you all were to him.  I am very sorry for your loss.

Scott

My condolences to Timothy's family. Life is not fair. Words can’t describe how sorry I am at this loss.

Tim was my mentor, my advisor

Tim encouraged me to be perseverant.

I would like to send my thoughts and condolences to you Julia and your boys,

He was the most important mentor and advisor in my scientific career. He was a great person and a great scientist.

He taught me how to be a good scientist. He always supported me when I need it most.

I will be forever grateful for his advice and support.

I will always be grateful to have had the opportunity to learn from him.

Thanks Tim